Sample Table Sort

Authors

Stephanie Fekete (McMillen Jacobs Associates) , Steve Skelhorn (McNally),
Allen Mitchell (Greater Vancouver Water District), and Tim Langmaid (Hatch Mott MacDonald)

Abstract

The Port Mann Main Water Supply Tunnel project provides a critical water main crossing of the Fraser River for the owner, Greater Vancouver Water District (Metro Vancouver). The project consists of two 60-meter-deep slurry wall shafts and a 1-kilometer-long, 3.5-meter excavated diameter tunnel located near Vancouver, British Columbia, Canada. The initial tunnel lining is a precast steel fiber reinforced segmental lining. The final lining is a 2.1-meter-diameter welded steel pipe, grouted in place with cellular concrete. This paper describes the challenges encountered during tunnel construction and the solutions implemented. Key challenges include earth pressure balance tunneling at up to 6 bar pressure, passing under a major rail yard, confined work spaces, a river crossing without surface access for the majority of the tunnel drive, ground freezing from a river platform for a critical TBM intervention, and boring through cobbles and boulders in dense glacial till.

Stephanie Fekete, P.Eng

Bio

Stephanie Fekete, P.Eng, is a geotechnical engineer with McMillen Jacobs Associates in Vancouver, British Columbia. She has over 5 years experience working on a number of major Canadian tunneling projects including the Ottawa LRT tunnel and stations and the Evergreen Line bored tunnel. Stephanie’s particular expertise is in geotechnical instrumentation, tunnel settlement and impact assessments, geological characterization and tunnel support design. She received her Master and Bachelor degrees in Geological Engineering from Queen’s University, Kingston, Ontario.

Authors

Kazunori Jimbo

Abstract

The Toyama line is under construction as a natural gas pipeline with 102km extension from Itoigawa to Toyama. Of the pipeline, 2km tunnel discussed here is excavated in mountain area after re-routing originally planned in urban area by open-cut method.

The tunnel is excavated in collapsible fractured breccia slate and Holocene sandy soil. Tunnels of Hokuriku Expressway and Hokuriku Sinkansen are in service above the tunnel route.

From the starting shaft in Toyama side, conventional tunneling was adopted to excavate the base rock layer and secure enough distance from the Hokuriku Expressway tunnel. From the starting shaft in Itoigawa side, TBM tunneling was adopted to cope with the unconsolidated soft ground of 200m length from the shaft.

We will discuss the issues and countermeasures concerning the selection of tunnel route and excavation method, and underground connecting method of conventional and TBM under high groundwater pressure up to 1.4MPa.

Kazunori Jimbo

Bio

Jinya Mitsui is a civil engineer in Obayashi Corporation, one of the major construction contractors in Japan. He is currently engaged in tunneling works of Toyama line gas pipeline project, as a site supervisor for construction management. He majored in civil engineering at Graduate School of Engineering, Kobe University. He studied a research on the watertight embankment using L-shaped geosynthetic drain and obtained Master of Engineering in 2009. He joined Obayashi Corporation in 2009, and experienced construction management in 2 conventional tunneling job sites of the Shin-Tomei Expressway and the Kyushu Shinkansen railway. During his career, he belonged to shield tunneling technology department in headquarters of Obayashi Corporation to technically support the shield tunneling job sites nationwide and to work on technical proposal of bidding for design and build works. Concurrently, he has been working in research and development on shield tunneling technology.

Authors

Bjorn Nilsen

Abstract

Swelling minerals may cause significant stability problems and in worst case cave-in, as has been experienced in several tunnel projects.

For index testing of swelling potential, a test procedure based on testing swelling pressure under constant volume is often used. This laboratory measured swelling pressure is however not identical to in-situ swelling. Investigations carried out at NTNU have shown that in situ swelling pressure is often < 50% of that measured in laboratory.

Also, if several samples are taken at the tunnel face of gouge from the same fault/weakness zone, quite different results may be achieved. Consequently, there is often uncertainty related to use of test results for support design.

This paper will describe test procedures which are used for characterizing swelling clay and discuss the significance of swelling pressure testing for tunnel support evaluation and design. Examples of support design in cases with active swelling clay will be given.

Bjorn Nilsen

Bio

Professor of engineering geology at NTNU, the Norwegian University of Science and Technology, since 1985. Experience from consulting and mining industry before joining the University. Former President of the Norwegian Tunnelling Society (NFF).

Extensive experience on various aspects of rock engineering, including site investigation, planning and design, stability analyses and construction control. Expert advisor of several large projects in Norway and abroad. Main current projects on subsea tunnelling, engineering geological aspects of mechanical excavation, hydropower projects and rock slope stability.

Chairman of the Scientific Committee for the upcoming ITA World Tunnel Congress in Bergen, Norway in 2017.

Authors

Stefano Fuoco

Abstract

The excavation of a Tunnel inside highly weathered and strongly fractured rock masses due to tectonic actions is still a challenge. In addition to the “ordinary� problems, the item related to the productivity must be considered when excavating a wide highly fractured area and a detailed study both of construction solution and monitoring system are required, to minimize the process time, and to optimize the adopted consolidation interventions, congruently to a pre-defined matrix of interventions.

In this paper, some interesting data acquired during excavation of a system of tunnels for Brennero Railway Base Tunnel between Italy and Austria, through the fault line between the European tectonic plate and the African tectonic plate, in which a system of tectonic faults created several hundred meters of de-structured rock mass, are summarized.

The tunnels have an excavation diameter from 6 to 10 m and overburden from 450 m to 800m.

Stefano Fuoco

Bio

Degree in Civil Engineering (1984) and Master Engineering in "Mechanised Tunnelling" (1994) at Politecnico di Torino. Visiting professor at Ancona and Trento University for the course of “Design of Underground Works�. At the present: Technical Director of Tunnelconsult (Barcellona).

Authors

Rohola Hasanpour

Abstract

Double Shield TBMs can be used in fast track project completion where there is limited information available on ground conditions and there are possibilities of encountering weak ground and shear zones. As such, DS-TBMs are the primary choice of the machines in long tunnels, but face the possibility of entrapment in squeezing ground, which entails long delays and major risks. This paper discusses the issues related to the application of machine in squeezing ground and results of numerical modeling, including the ground pressure on the shields and required propelling thrust to overcome shield friction. It also examines the possibility of using ground improvement methods to increase ground strength, and thus, increase their capability of the machines to cope with squeezing ground conditions. In this study, 3D finite difference simulation of a double shield TBM in squeezing ground was performed to estimate the operational parameters, in particular machine thrust.

Rohola Hasanpour

Bio

Dr. Rostami is currently an associate professor and Centennial Chair of Carrier Development in Mining at the department of Energy and Mineral Engineering, the Pennsylvania State University (PSU). He has got his BSc university of Tehran (UT), Faculty of Engineering (Fanni) in 1987. He subsequently started his graduate degree at Colorado School of Mines (CSM) in 1989 and got his MSc and PhD in mining engineering in 92 and 97, respectively. Dr. Rostami has over 25 years of experience in design, management, research, and teaching in the field of mining, tunneling, and underground construction. Dr. Rostami is a registered Professional Engineering (PE) in Maryland, Pennsylvania, and Virginia. He has published over 40 peer reviewed journal publication and 130 conference papers and many technical reports. He is a member of SME, ASCE, ARMA, ISEE, IRSME, IRRMS, and TRB tunneling committee.

Authors

Heinz Ehrbar, Hans-Peter Vetsch

Abstract

The Gotthard Base Tunnel, the longest railway tunnel of the world, will start the commercial operation in December 2016 after a history of more than 20 years of design and construction work. The decision on the various possible alternatives of the tunnel system has been taken in the early beginning of the project more than 20 years ago. The alternatives discussed were one tube (double track tunnel), two tubes (two single track tunnels) and three tubes (three single track tunnel or two single track tunnels with a service tunnel). A cost-benefit-analysis regarding the construction time and also the entire life time, lead to the decision to construct a tunnel system consisting of two single track tubes with an elevated safety standard (cross links and large multifunctional stations). The decision-making criteria were the construction (time, cost, environmental aspects), the future operation (productivity, preservation and maintenance, operation costs) and safety aspects (risks, public opinion). The paper shows the effects of the meanwhile increased requirements on safety and maintenance and gives recommendations on the most important factors to be taken into account future projects. Increased requirements on future projects may lead to other technical solutions than the concept realised for the Gotthard Base Tunnel.

Heinz Ehrbar, Hans-Peter Vetsch

Bio

Authors

Rakesh Sehgal

Abstract

SJVN Limited successfully commissioned its Rampur HEP (412 MW) in 2014. The project has been planned to operate in tandem by directly utilising the Tail Water of SJVN’s prestigious Nathpa Jhakri Hydro Power Station 1500 MW located upstream. The initial filling of voluminous water conductor system having 10.50 m diameter, 15 Kilometre long Head Race Tunnel, involved more than 1.5 million m3 of water. The filling operation of such a large diameter tunnel constructed in young folded Himalayas which always offers less ideal sites for tunnelling and their subsequent operations under pressurised conditions is worth sharing with tunnelling fraternity. The paper shall cover meticulous planning, execution, precautions taken, and performance monitoring during filling process keeping in view the fragile geology, low rock cover zones, shear zones in close vicinity of thickly inhabited areas, squeezing zones, hot water zones encountered during excavation.

Rakesh Sehgal

Bio

Rakesh Sehgal graduated in Civil Engineering from Shivaji University in 1989. From 1989 to 1994 he worked for HPPWD as Design Engineer. He joined SJVN Limited, India in 1994 and worked at various levels in Tunnel Design Wing of Nathpa Jhakri HEP (1500 MW) specializing in design of large dia. hydraulic tunnels from concept to commissioning. After commissioning of NJHEP in the year 2003 he remained associated with design of 15 Km long 10.50 dia. Head Race Tunnel of RHEP (412 MW) from concept to commissioning, Consultancy Services for Railway Tunnels and Station yards of KRCL’s USBRL Project in J&K and R&D projects of SJVN. At present he is working as DGM civil Design and looking after Designs of company’s another Hydro project named Devasari HEP 252 MW and consultancy services for road tunnels.

Authors

Georgios Kalamaras

Abstract

The Caltanissetta twin roadway tunnel is 4km long and is excavated in clay formations apart from a 200m stretch of folded crushed limestones embedded in clay. Maximum overburden is 125m while the maximum hydraulic head is 11bar.

The geometry of the rings was developed in a close cooperation with the TBM manufacturer. The 60cm ring static design for the NFM 15.08m EPBS was based on 2D and 3D numerical modeling. Geotechnical design included face pressure estimates and subsidence evaluations.

A risk management plan was compiled that incorporated all of the important TBM parameters. Systematic monitoring of the segments and surface ground settlements was conducted. Excavation parameters were registered all along the tunnel excavation.

Average advance rate was in the range of 16-20 m/d, the record in ring building was fifteen 2m-long rings per day. In this moment the TBM is transported for the construction of the second tunnel.

Georgios Kalamaras

Bio

Georgios Kalamaras, co-founder of the AK Ingegneria Geotecnica Srl, is an engineer with 20 years of experience in the field of tunneling design. He obtained his PhD working with Z. T. Bieniawski in the field of tunneling risk analysis. In AK he leads the team of calculations design and risk analysis.

Authors

William A. Cao

Abstract

The East Side Access (ESA) CM005 Contract - Manhattan South Structures - consists of the installation of the waterproofing and final concrete lining for railroad tunnels, 3-Level Wye track turnout structures, segments of the Main Cavern Station, and a series of Ventilation Structures excavated beneath the existing Metro North Railroad (MNR) Grand Central Terminal. The duration of this Contract was originally 29 months, however, because of several key team decisions made collectively by the CM, Designer and the Contractor, it is projected that this Contract will be completed months ahead of its schedule. These strategies include the use of alternate construction methods, including the use of sprayed concrete lining and precast lining. This paper discusses these strategies, and illustrates how successful teamwork and cooperation during the execution of a large-scale construction project can lead to lowering costs, improving quality, and reducing the overall project schedule.

William A. Cao

Bio

William Cao is a senior structural engineer and has been with Parsons Brinckerhoff for over 15 years. He has been working on the East Side Access project for the past 10 years, and have served as the structural team lead during the design and construction of the Manhattan South Structures Contract.

Authors

William P. Levy

Abstract

The District of Columbia Water and Sewer Authority (DC Water) is implementing its $2.6 billion Long Term Control Plan (DC Clean Rivers Project) for the District’s combined sewer system. The First Street Tunnel project is part of DC Water’s 13 mile Anacostia River tunnel system, currently under construction in the oldest, most densely populated section of a highly urbanized environment. The success of large public works projects depends on a well informed and supportive public. With the local community impacted by flooding but concerned about heavy construction impacts, the paper details the components of a successful public outreach plan and lessons learned. Early identification of community mitigation, working cooperatively with stakeholders, frequent dissemination of accurate information, including public meetings, required the Project Team to establish a culture of problem solving collaboration with the community.

William P. Levy

Bio

Bill Levy currently works for the District of Columbia Water and Sewer Authority under its $2.6 billion Clean Rivers Project as Program Manager, Tunnel Design. He is the design Project Manager for the First St. Tunnel and the upcoming Northeast Boundary Tunnel.

For the 20 years prior to joining DC Water, Mr. Levy was Geotechnical Program Manager for the Massachusetts Water Resources Authority, where he oversaw all geotechnical works and was Project Manager for the North Dorchester Bay CSO Storage Tunnel, and Boston 019 CSO Storage Conduits among others.

Mr. Levy is a licensed professional engineer and has a bachelor’s degree in geology from the University of Rhode Island and a master’s degree in civil engineering from the University of California at Berkeley.

Authors

Steven W Hunt

Abstract

Mr. Hunt co-authored paper called “Global Experience with Soft Ground and Weak Rock Tunneling under Very High Groundwater Heads� for the NAT 2006 conference. It summarized global experience on nine projects with tunneling at heads from 5.5 to 11 bar. Since then, additional projects have been completed with heads ranging from 7 to 15 bar including: Lee Tunnel in London, Brightwater near Seattle and Lake Mead Intake No. 3 in Nevada. This paper summarizes new experience with pressurized face tunneling at groundwater heads ranging from 7 to 15 bar. Particular emphasis will be given to the author’s direct experience on the Lake Mead Intake 3 and Brightwater projects. For each project, pressure issues during TBM advance and when completing cutter change interventions are discussed. Recommendations are given on approaching the key challenges faced when planning and completing pressurized face tunneling at very high groundwater heads over 7 bar.

Steven W Hunt

Bio

Steven W. Hunt, P.E., is a senior geotechnical engineer and tunneling technologist with CH2M. He has over 38 years of experience with tunneling and underground construction after receiving BS and MS degrees from the University of Illinois. Steve has authored or co-authored over 30 papers on design and construction of shafts and tunnels and has frequently lectured at Colorado School of Mines short courses. Mr. Hunt has provided geotechnical and tunnel engineering services on projects across North America and within the United Kingdom, Chile, Guatemala, Hong Kong, Singapore, Australia, India, Kuwait, Saudi Arabia, Qatar and United Arab Emirates. Since 2004 he has been actively engaged in projects with high pressure tunneling having groundwater heads in the range of 5 to 15 bar.

Authors

Santiago Veyrat, Marcos Sancho, José M. Galera

Abstract

Cheves Hydropower Project is located in Peru and consists in approximately 20 km of tunnels and two caverns. Most of the Headrace tunnel has been excavated in igneous and metamorphic rocks with high overburden. A high number of stress release events took place during the excavation of the tunnels and caverns. The intensity of these events varies from acoustic emission to a violent rockburst. Rockburst and stress releases took place mainly in the headrace tunnel and the powerhouse complex. Headrace tunnel was excavated in sedimentary deposits (coal and sandstones), andesite, volcanic breccias, granodiorites and hornfels. Most part of the events took place in areas excavated in igneous and metamorphic rocks.

A specific stress risk assessment was done in addition to the geological assessment at the tunnel face during the tunnel excavation, in order to collect all the information coming from the tunnel. Three stages were defined to manage the risk of rockburst or stress releases. These measures can be classified in prediction, prevention and protection.

A stress release classification was developed for the project based in previous experiences from the main contractor in the Gothard Tunnel. This classification was divided in four categories according to the characteristics and effects of stress releases.

There are several scales for rockburst in the literature, here it is presented a back analysis executing a comparison between some of these scales and the events occurred at the Cheves Project. The following methodologies are applied to stablish the scale of the rockburst that theoretically could have happened during the project:

· Strength Index (RSi). Hawkes (1966)
· Strain Energy Density (SED). Poland (1994)
· Stress Index (Si). Yoon (1994)
· Competency factor (Cg). Palmstrom (1995)
· Stress Coeficient (Sc). Wang (1998)
· Overtressing Analysis. Hoek and Marinos (2009)
· Overstressing. Diederichs et al. (2010)
· SFR Factor - Q-System (NGI, 2013)

These classifications shows a highly variability of results that will be compared with the classification applied in the Cheves Project in order to check the accuracy of these scales.

Santiago Veyrat

Bio

Since 2001, Mr. Veyrat's professional career has developed within the field of Applied Geology (geological mapping, geology and geotechnical prospection) and, specially, in the field of Geotechnical Engineering. In the latter, Mr. Veyrat has taken part in a number of different studies and surveys (railways, roads, tunnels, hydraulics and building).

Mr. Veyrat has been involved in all stages of a project, from field works executing geotechnical investigation up to geotechnical design, both as part of a staff and as coordinator of a multidiscipline team. Since 2012 Mr Veyrat is involved in tunneling projects under high stress conditions in the Andeans. Mr. Veyrat and Mr Sancho have develop a Qualitative Rockburst classification for civil projects based in the effects of the stress release.

Authors

Galip Devrim ERYILMAZ

Abstract

Sütlüce Tunnel is located in an old settlement area of Golden Horn, where there are many old buildings with high population. The tunnel was planned to support the solution of inner city traffic. The construction area was formed by carboniferour, neogen and quartener old formation. There exists also ancient fill and debris over alluvional deposit. During design and construction phase of project utmost care has been given to avoid damage of existing old buildings and failure in excavation and support of tunnel. In order to provide reliable and safe construction, a detailed rehabilitation program was implemented. In this paper; design, construction, detailed monitoring and rehabilitation are reviewed.

Galip Devrim ERYILMAZ

Bio

Galip Devrim ERYLIMAZ was graduated from Hacettepe University Mining Engineering Department. He is chief engineer for tunnel design.

Authors

Giuseppe Lunardi, Giovanna Cassani, Andrea Bellocchio

Abstract

The Stretch of the Italian High Speed Train between Genoa and Milano is currently under construction with more than 78 km running tunnels and construction and safety adits. The excavations will be both conventional and mechanized and will be completed by 2018.

The paper describes the experience gained in the excavation of the Castagnola and Val Lemme adits, two tunnels of about 10 m in diameter driven under severe squeezing conditions. The ground faced along these tunnel is a low strength scaly clay, highly tectonized, with overburden ranging from 100 to 600 m. A viscous-plastic model of the ground was implemented to validate by back analyses the evidences collected during the excavation works.

The excavation of the two tunnels was performed completely full face, using proper grouting interventions of the rock mass, like cemented fiber glass elements at the core/face of advance and self drilled radial bolts.

Giuseppe Lunardi

Bio

Managing Director of Rocksoil S.p.A. - Civil transport engineer, graduated from the Polytechnic of Milan, he has taken part in the design and consultancy of the most important tunnelling work carried out in the last years in Italy and abroad. The particularly innovative spirit that has always inspired the design of Rocksoil S.p.A. led him to live close to the major experimental sites, such as that of Nazzano Tunnel, located near Rome, where the widening of an existing tunnel without interrupting traffic was successfully carried out for the first time over the world. He is also Vice-President of the Italian Tunnelling Society (SIG) with the delegation of Chairman of the section on "Conventional excavation". In this role he was involved in the organization of the most important sector conferences organized by the International Tunneling Association (ITA).

Authors

Karl Grossauer, Thomas Marcher, Peter Gferer

Abstract

The Alto Maipo Hydroelectric Power Project is currently the largest hydropower project under construction in Chile with a total capacity of 531 MW. The scheme includes two underground power houses and in total 67 km of tunnels excavated by D&B and thress TBMs. Construction of the underground works started in August 2014.

A short introduction of the project is followed by a description of the rock types being expected in the underground works. Ground Hazard Types are established based on the information from field investigations and the experiences made from the nearby Alfalfal I tunnel. Besides disontinuity controlled hazard types rock burst, rock squeezing with long term creep, and swelling or dissolution is expected which is typical for volcanic rock types. The ground and stress conditions which govern these hazard types will be discussed in detail.

Rock mass characterization is done according to various classification systems such as Q-value and RMR. The support selection takes different design philosophies (NATM versus Norwegian approach) into account. Lessons learned so far will be presented.

The paper will conclude with an overview of already excavated tunnel stretches and ground conditions and ground behaviour observed.

Karl Grossauer

Bio

Grossauer Karl graduated at Graz University of Technology with MSc degree (2001) and with PhD (2009) in Geotechnical Engineering and Rock Mechanics. He is the Director of the Tunnelling Division at Amberg Engineering Ltd. in Switzerland. Since April 2014 he is Technical Director of the Owners Engineer for the Alto Maipo HEPP in Santiago, Chile.

He actively contributes to research and development in underground engineering and has gained in his position as Tunnelling Director and project manager an considerable experience in consulting and design in the field of underground construction. He has done the geotechnical and structural design for a number of well-known and challenging tunnelling projects with respect to high overburden and fault zones such as the Semmering Base Tunnel (Austria), Gotthard Base Tunnel (Switzerland), and Stockholm Bypass Project and was involved in large underground projects in Switzerland, India, South America and Singapore. He is Deputy Head of the section Rock Mechanics and Rock Engineering of he Austrian Society of Geomechanics.

Authors

Franz Wilhlemstoetter, Christian Karner, Bradford Townsend

Abstract

The Confederation Line is phase 1 of Ottawa’s light rail transit, which consists of 15 stops and stations with 12 stops above ground. The project’s center piece is a 2.5km long tunnel with three underground stations leading underneath downtown Ottawa and is constructed within feet of adjacent buildings. Station caverns are approximately 16.5m by 18m in a horseshoe configuration for the 2 downtown stations that are constructed in rock while Rideau Station is approximately 22m by 18m in an oval configuration constructed in mixed ground. The paper will discuss design decisions made early on in the project such as excavation method and unique construction sequencing, machine selection, and corresponding progress rates. The paper also documents construction and design challenges such as construction of large caverns in very close proximity to existing buildings as well as changing ground conditions. Finally, an overview of achieved construction milestones and a current construction progress will be presented. Station cavern excavation is expected to be completed in late 2015.

Franz Wilhlemstoetter

Bio

Authors

Edoardo Misano, Jean-Louis Cubray, Fabiola Espinoza Carmona, Elena Chiriotti

Abstract

Within the context of the Alger-Oran railway project, the excavation of the Ganntas Tunnels (doubletube, cross-section 75m2, length 7500m) encountered a highly fractured and laminated clayey marl rock mass under 100m of overburden in correspondence of a fault zone.

When the tunnel reached the soft rock formations, with presence of shear plans filled by clay especially at crown, extreme squeezing problems occurred and the excavation had to be stopped. Convergences of 0.7m at crown were registered before the bench excavation. The anomalous deformations caused support failing and re-profiling operations were needed for more than 100m. In order to study the phenomenon and the potential failure mechanisms to find a more adapted support type and construction sequence, the rock mass behavior and the tunnel response have been backanalyzed by using finite element modelling calibrated on geological observations and on monitoring data.

The analyses, conducted in plane and axisymmetric conditions, permitted to identify the stress-strain state at each stage of the construction sequence. The information provided by the analyses is of relevance in modelling tunnel response in extreme squeezing conditions and in getting indications for a more appropriate tunnel support and construction sequence.

Edoardo Misano

Bio

Edoardo Misano is a civil engineer full marks graduated at the University of Rome "La Sapienza" in Geotechnics. He has worked for two years in Rocksoil in Milan as a geotechnical and tunnel designer involved in various infrastructural projects at construction stage as "Pedemontana Lombarda" highway, "Lyon-Turin" high speed railway and the new "Brenner Basis Tunnel". Since May 2014 he has been working in SYSTRA in Paris where he joined the Tunnel team working on the draft project of the Greater Paris Metro Line. For SYSTRA he participated, as specialist in underground structures design, to the Security Commission of the Frejus Tunnel when it had to decide whether works for the construction of the new underground laboratory (LSM cavern), situated in between the two tubes, could damage existing tunnel structures.

Authors

Edward Batty, Nathan Bond, Eleanor Kentish, Alan Skarda, Simon Webber

Abstract

Crossrail is Europe's largest construction project - a new 100km rail route running through central London. A joint venture of BAM, Ferrovial and Kier (BFK) is constructing the tunnels and escalator shafts at the new Bond Street and Farringdon Stations.

The recent trend in the UK industry towards sprayed secondary linings is driven by the potential for significant savings in cost and time. BFK is unique within Crossrail by constructing both sprayed and cast secondary linings.

This paper presents a direct comparison between sprayed and traditional cast in situ secondary linings at Bond Street and Farringdon Crossrail Stations. An objective comparison is drawn between procurement and mobilisation periods, production rates, flexibility, tolerances, quality and logistics in the tunnels. The technical challenges surrounding cast and sprayed secondary linings are explored, and recommendations are made of how each method could be improved for future use.

Edward Batty, Nathan Bond, Eleanor Kentish, Alan Skarda, Simon Webber

Bio

Edward Batty graduated from University of Surrey in 2012 with a MEng Civil Engineering Degree. Edward has spent the last 3 years working on Crossrail Contract C300/410 for Team BFK.

Nathan Bond graduated with a MEng from UCL in 2011. Nathan worked on the Tottenham Court Road station upgrade before moving to Farringdon where he is Sub-Agent for SCL works.

Eleanor Kentish obtained a MEng in Civil and Structural Engineering from the University of Leeds. Following two years in design, Eleanor joined BFK and is Section Engineer at Bond Street.

Alan Skarda studied engineering at Cambridge University. After a period in temporary works design with Kier, Alan became a Section Engineer at Bond Street Station and obtained Chartership in 2015.

Simon Webber graduated from Imperial College with a MEng in 2010. Simon has worked for Kier in temporary works design before joining BFK as a Materials Engineer for Farringdon Station.

Authors

Dan Ifrim

Abstract

Mechanized tunneling is a safe and effective alternative to other methods in terms of schedule and cost. The success of a mechanized tunneling project involves a comprehensive and interdisciplinary consideration of all contributing factors such as geotechnical investigation, design, technical specifications and TBM selection.

Amongst mechanized tunneling project challenges the operation of the TBM is one of them. Its efficiency can be severely affected by inappropriate TBM selection or operation by inexperienced workers. The objective of this paper is to address the importance of TBM crew skills and qualifications and principally the TBM Operator.

The paper addresses the Owner and Consultant involvement in the selection and pre-qualification of the TBM crew with specific to TBM operator as well as the role of Contractor and TBM manufacturer in TBM operator training. One step further this paper explores the potential of issuing a TBM operator license, periodical training and certification programs.

Dan Ifrim

Bio

Dan Ifrim is a TBM and tunnel construction specialist with Hatch Mott MacDonald tunnelling practice. His current role is Senior Project Manager with the Tunnel Group in Mississauga, Ontario Dan graduated in 1983 from University of Bucharest, Romania with a Mechanical degree.

He has over 30 years engineering and project management experience in construction projects with over 12 years in mechanized tunnelling.

His past and current roles includes design, project management, contract management, risk assessment, risk management and cost estimates for tunnel projects in North America, Europe and Asia.

Authors

Andrew Thompson

Abstract

As part of the Metropolitan Transportation Authority's $10.5bn East Side Access Project in New York, 3200m of tunnel had to be constructed in glacial till beneath a railroad junction handling over 800 trains per day. The use of risk based decision making tools was essential in developing the bespoke contract framework that was adopted as well as making informed decisions once excavation commenced. This paper will outline the risk management process adopted, discuss the risks and mitigation strategies adopted and comment on the impacts of this approach on the as built project cost and schedule. In particular, the paper will outline the unique approach used to establish the baseline against which the Contractors performance would be measured as the selection of a Slurry TBM to excavate the tunnels was considered to compromise the effective use of a Geotechnical Baseline Report.

Andrew Thompson

Bio

Andy has worked for Mott MacDonald since 1988, primarily in program and construction management roles. Currently serving as Program Executive on the Metropolitan Transportation Authority’s $10.4bn East Side Access Project , where he is responsible for delivering the heavy civil and underground portions of the project by July 2019 to enable revenue service to commence in 2020.

Previously Andy has worked on landmark projects such as Channel Tunnel, the A20 Round Hill Tunnels, Great Belt in Denmark as well as other underground projects such as Harbor Area Treatment Scheme Stage 1 in Hong Kong, Greater Istanbul Water Supply Project and Atlanta West CSO project.

Authors

Mohammad Saleem

Abstract

On an underground construction projects, effective Quality management is essential to ensuring facility durability, life cycle performance and low maintainability. Furthermore, follow on contracts also rely on an effective Quality management system for interface congruency.

For the past 15 plus years Central Puget Sound Regional Transit Authority’s Link Light Rail extension has successfully completed over 10 miles of twin bore tunneling and associated underground features including cross passages, deep sump structures and shafts. After the completion of each segment, lessons learned have successfully been implemented to improve the quality of delivered projects.

This paper presents the Sound Transit Quality Management System with regard to a number of project elements of tunnel construction projects, with specific focus on Quality performance of TBM boring, launch box excavation, segment construction, cross passages, slurry walls, and other associated construction features. A collaborated Total Quality Management System will be presented in this paper that will serve as a guide of successful Quality implementation.

Mohammad Saleem

Bio

Mohammad Saleem is a seasoned engineering professional with over 19 years experience in design and construction acquired while working on mega projects in the United States and International. He has been with Sound Transit for the past five years and is currently the Senior Quality System Manager for Sound Transit on projects like University Link ($1.9 Billion), Northgate Extension Link ($2.1 Billion), East Link Extension ($2.8 Billion) and Lynnwood Link Extension ($2 Billion). He is a licensed Professional Engineer in the state of Washington and a certified Auditor with the American Society of Quality. He holds a BSCE and a Certificate of Heavy Construction Management from the University of Washington. He has lived the in the Seattle, Washington are for the past 35 years and enjoys playing sports and outdoor activities. He is married and has three children.

Authors

Eivind Grøv

Abstract

Tunneling is related to handling of uncertainties, risks associated with geological conditions are significant and 'unexpected geological conditions' often claimed. Unit rates contracts are used with bid-build model, it shares risk between owner and contractor, owner retains the risk for geological conditions while contractor carries risk for performance efficiency. Rock strengthening is determined assessing rock mass quality encountered at tunnel face. Actual quantities may differ from the contract’s BoQ, a flexible contract is required to enable adjustment of actual quantities. Variations of quantities involve a clause to adjust construction time.

Unit price contracts deals with 'unexpected geological conditions', if the 'unexpected' element results in variations in quantities. Work activities have quantities and 'standard capacities' for regulation of construction time. Variations in quantities are expected in tunnelling and hardly deserve the term 'unexpected'. If unforeseen geological features necessitate work not included in the BoQ, the contract must be supplemented. Fixed price contracts may not provide the intended predictable cost. 'Adjustable fixed price' contracts, combining unit rate and fixed price, may prove suitable. This paper uses sub-sea tunnels to demonstrate its suitability

Eivind Grøv

Bio

Eivind Grøv graduated from NTNU (University of Science and Technology in Trondheim) in 1983, MSc. in Geotechnical Engineering. Grøv has worked as consultant in the tunnelling industry covering tunnelling and underground applications for oil/gas storage, hydropower, road/railway tunnels and sub sea tunnels in rock. His experience includes expert services to a wide range of projects in more than 20 countries.

Grøv is Chief Scientist at SINTEF heading research works. He is Professor in his fields at NTNU lecturing/supervising students at MSc and PhD levels. He has been invited lecturer and keynote speaker on several international conferences with a large publication production.



Grøv is past President of the Norwegian Tunnelling Society, and past Vice President of ITA concluding a period of 6 years in the Executive Council. Grøv is now President of the Norwegian Tunnelling Network. Grøv has held numerous duties in international organisations and is currently Animateur of ITA Working Group on "Sprayed Concrete use". He also leads several tasks within the Norwegian Tunnelling Society.

Authors

Thomas Konstantis

Abstract

Tunnelling and Underground works are unequivocally subject to a diversity of inherent uncertainties associated with the geotechnical, hydro-geological and environmental regime that surrounds them. On many occasions, these uncertainties could provoke loss events of considerable consequences. The present contribution elaborates on losses that the insurance market has suffered in the recent years, following a construction failure event. These losses are being assessed and analysed on a quantitative basis through evaluation of cost related data, with explicit discretization of the applied construction methodology and of the subsequent developed failure type since both of which are considered of major importance. Given the identified persistence and regularity of some loss-contributing factors, recommendations are provided on the basis of a proactive approach that are envisaged to reinforce the understanding of project risks and alleviate the incurred insurance cost.

Thomas Konstantis

Bio

Thomas Konstantis is a Civil Engineer, graduated in 2000 from National Technical University of Athens, from where he has also received his MSc, titled "Design and Construction of Underground Works" in 2002.

He has more than 14 years of professional experience involving active roles in senior positons in international consultant engineering firms, like CH2MHILL and Hyder in Dubai and "O.T.M" in Greece. His consultant experience is coupled with regular and extensive involvement in construction sites.

Currently he is working in the insurance industry with Marsh in London as their in-house Risk Engineering Consultant providing technical consultancy and project reviews in his specialized area of management & design of underground, geotechnical & structural works.

Thomas has also involvement in the academic field acting as a part time Lecturer in the Heriot-Watt University in Dubai in the field of Geotechnical Engineering and as an Engineering Mentor in the UCL, London, UK.

Authors

Yun Bai

Abstract

It is well known that tunnelling involves extreme complexity and a high degree of risk. Conventional risk control processes only evaluate risk at the beginning of the project and combine the loss and risk probability. However, environmental factors may change during construction which modify the initial risk evaluation. This paper takes these factors into consideration and introduces a new risk control method. The Multiphase Risk Management Method combines dynamic control and timely risk assessment throughout the construction process. Not only is the initial risk taken into consideration before the start, but also the secondary, and third risk encountered with mitigation measures during construction. A case study of this method is given based on the Ningbo Metro Line for the first Oval shield tunnel in China. A risk control system is set up and proved to be suitable and efficient.

Yun Bai

Bio

Ang Chen is a first year Civil Engineering graduate student at Tongji University. He is from Chengdu, Sichuan Province, in the PR China. In 2014, Mr. Chen graduated from Wuhan University with a bachelor’s degree in Civil Engineering. Ang Chen's emphasis is on the development and utilization of underground space. Under the mentorship of Professor Yun Bai, Mr. Chen’s focus is to innovate new technology and research risk management in Tunnel and Underground Structure Engineering. Projects that he is currently working on are developing the Ring Pipe Jacking Method (RPJM), multiphase risk management for the first oval shield tunnel project in China, underground wind-flow-aided bike lane system and research in pneumatic excavation of lunar soil simulant.

Authors

William Gerard

Abstract

In response to tunneling industry requests, the Colorado School of Mines developed curricula for the training of those responsible for tunnel rescue teams in 2014. The course is recognized by MSHA (Mining Safety & Health Administration) for advanced mine rescue training and provides in depth information beyond what is required by OSHA (Occupational Safety & Health Administration) 29 CFR 1926.800. The focus is on regulatory comparison and obligations, emergency preparedness, team organization and leadership, surface organization and incident command, exploration and underground search and rescue, firefighting, ground control, gases, tunnel ventilation, basic emergency medicine and special hazards. Included is hands-on training with gas detectors and breathing apparatuses and observation of an underground rescue team training. Parsons Corporation, the Colorado School of Mines, and the City of Akron Ohio, are cooperating to incorporate this training for the Ohio Canal Interceptor Tunnel Project (30' EPBM bore) that is scheduled to commence November 2015.

William Gerard

Bio

Mr. Gerard the Construction Manager Ohio Canal Interceptor Tunnel Project ("OCIT") which is a 27' finished diameter CSO tunnel. He has worked for some of the largest tunnel contractors in North America. He is an expert constructing and costing shafts and tunnels in heavily congested urban environments in North America and Middle East Africa Divisions at Parsons Corporation. He participates in management of self-performed installation of shafts, tunnels and caverns for water/sewer and transportation projects. He has managed large field forces of engineers and craft for the execution of these mass underground excavations of up to 1 million cubic yards of soil and rock by hydromill/slurry, road header, drill/shoot and tunnel boring machine. Mr. Gerard is the Lead Tunnel Estimator for Parsons Corporation.

Authors

Lena Paar, Detlef Heck

Abstract

Underground construction poses certain challenges for all parties involved because the actual ground conditions are often unpredictable. Highly complex projects like tunnel construction projects are affected by various uncertainties. To address this complexity the construction contract has to be flexible enough to be adapted to the actual conditions (e.g. divergent ground conditions, delays of work). However, the adaptation of a tunnel construction contract does not guarantee the absence of an interpretation margin. The perfect construction contract is an illusion because ex ante-statements of the actual ground conditions are not feasible. This paper will discuss contractual parameters that must be considered in order to enable an effective adaptation of the contract during excavation. It is therefore necessary to discuss the following topics: decision-making competence, variable remuneration, fair risk allocation, partnering between client and contractor and Value Engineering.

Lena Paar

Bio

Authors

John J Reilly

Abstract

Correct application of risk correlation, dependencies and linkage allows owners and contractors to explicitly determine more realistic risk-based costs and risk mitigation strategies. This paper will outline methods to deal with correlation, dependencies and linkage and will consider risks that may occur multiple times. Practical comparisons of results – with or without these elements – will be presented.

While the basic elements of risk management including probability, consequences, risk registers, mitigation measures etc. are now well understood, the process of correlation, dependencies and linkage of risks and risk scenarios is less well defined and understood.

For example, a risk register may list several discrete multi-million dollar potential risk events but may not consider that one risk may trigger another risk (completely or in part). If such risks are correlated, this may mean that a one $5 million risk may trigger other risks, with a potential exposure many times that amount.

John J Reilly, P.E., C.P.Eng.

Bio

John Reilly has over 50 years experience in management, strategy, organization, technical review, management oversight, expert panel management, strategic advisory panels, team alignment, partnering, contacting and delivery methods, risk management and probabilistic cost/schedule analysis for large, complex infrastructure projects including tunnels, metro systems, highways and bridges. He has led several Expert Review Panels and Strategic/Technical Advisory Teams for recent megaprojects.

Previously, he was President of the American Underground Construction Association and Chair of two International Tunneling Association Working Groups – 13 (Benefits of Underground Structures) and 20 (Urban Problems, Underground Solutions).

He is a graduate of the University of Sydney (BE Honors) & University of California Berkeley (MS)

Authors

Hee-Young Chung, Jeongjun Park, Kang-Hyun Lee, Ki-Chang Hyun, In-Mo Lee

Abstract

In this paper, a construction risk management methodology applicable to shield TBM tunnels is developed which can take the predicted ground condition ahead of tunnel face during tunnel driving into account. The methodology can systematically assess the potential risk of undesirable events occurring during shield TBM tunnelling by quantitavely evaluating the probability and impact of the risks. It can also propose a counter plan for the potential risk utilizing Multi-Criterion Decision Making (MCDM) taking the cost and the time into consideration. In addition, the proposed method is applied to an EPB shield TBM tunnelling site where the actual problems occurred during tunnel driving, verifying the feasibility of cost savings if the proposed risk management methodology is adopted from the beginning of the project.

Hee-Young Chung

Bio

Graduate Student, School of Civil, Environmental and Architectural Engineering, Korea University, Seoul, Korea
Researcher, Institute of Underground Space Technology, Korea University, Seoul, Korea

Authors

Debra F. Laefer

Abstract

To more rigorously address tunneling risks to above-ground structures, a district-level approach is required. A major challenge to such a paradigm shift is the population of such a multi-block model. For unreinforced masonry structures, their external, above-ground geometries can be captured automatically by aerial remote sensing. However wall thicknesses, interior load-bearing elements, basements depths, and foundation types and layouts remain unknown without a prohibitively expensive building-by-building, on-the ground survey. To consider these features in an automatic way, a probabilistic framework is proposed. This allows a more rigorous, initial, risk quantification than is currently possible with the simple empirical models generally being used in industry. This paper introduces district-level considerations for a probilistic tunnel-risk screening tool.

Debra F. Laefer

Bio

Prof. Debra F. Laefer has been an active researcher in LiDAR for nearly a decade. She has a dual background in geotechnical and structural engineering, with a long-standing interest in urban security. Her research has been supported by the European Research Council, Science Foundation Ireland, and the United States' National Science Foundation (NSF), and while she was at the University of Illinois at Urbana-Champaign by the Ford Foundation through the Arms Control, Disarmament, and International Studies programme. In 2004, she was a faculty mentor with NSF Natural Hazards Mitigation in Japan programme and named a Fellow of Japan's Society for the Promotion of Science. She has been an invited speaker at the Brookings Institute and has authored over 100 peer-reviewed papers related to the protection of the built environment from natural and manmade activities. Prof. Laefer served as the chair of the Heritage and Existing Structures' Committee for the Earthquake Engineering Research Institute and began teaching classes on the protection of critical infrastructure from terrorist attack in 1998.

Authors

Nasri Munfah, Sanja Zlatanic, Mark Ramsey, Heiner Sander

Abstract

The unpredictable aspects inherent in tunnels or underground projects and the accelerated pace of the Design-Build (D-B) and Public-Private Partnership (P3) projects can result in additional geotechnical risks, unanticipated conditions, added costs, potential construction delays, and even expensive litigations if riskmanagement strategies are not established in advance and implemented early. Although the concept of fairness in geotechnical risk allocation in tunnels and underground projects is well understood, its implementation in D-B and P3 projects is complicated and challenging for various reasons especially the definition of the roles of the responsibilities of the participants and the risk allocation among them. Some potential risk mitigation measures include: advanced geotechnical investigations, full disclosure of the geotechnical data, judicious GBR, contingency funds, escrow bid documents, Dispute Review Board (DRB), risk register, etc.

This paper discusses these risks, identify potential measures and approaches for fair allocation of geotechnical risks, and pinpoint pitfalls to be avoided by owner when setting up D-B or P3 contracts. Lessons learned from previous projects including Alaskan Way Tunnel, Presidio Parkway, Istanbul Strait Crossing, and Crenshaw-LAX will be used for illustrations.

Nasri Munfah

Bio

Nasri Munfah is Chairman of HNTB Tunneling and Underground Engineering practice. He brings more than 30 years of experience in transportation, transit and underground engineering. He leads the tunnel and underground staff of over 100 people providing services nationally. He has been responsible for managing all phases of multi-billion-dollar multidisciplinary domestic and international tunneling projects from feasibility and conceptual level through final design and construction. He is a principal investigator and a co-author of Federal Highway Administration (FHWA) Technical Manual for Design and Construction of Road Tunnels, the first comprehensive manual for tunnel design in the USA. In addition, Mr. Munfah is an adjunct professor in Columbia University's Civil Engineering Department, teaching graduate level courses on the design and construction of tunnels and underground structures.

Mr. Munfah filled several roles on the Istanbul Strait Road Tube Crossing Project including project manager, Principal in Charge and most recently the Independent Design Verifier (IDV).

Authors

Alan Hodgkinson, David Caiden, Petros Fortsakis

Abstract

The "ITA Contractual Framework Checklist for Subsurface Construction Contracts" was produced by ITA Working Group 3 (WG3) Contractual Practices in 2010 and recently updated (2015). It identifies key contractual areas seen as ensuring successful subsurface construction. The Checklist was prepared because existing standard forms of construction guidelines and contracts do not adequately explain how to deal with the peculiarities of subsurface works. The document was based on the collective knowledge of the members of WG3, who together have worldwide underground project experience.

To determine if actual project results correspond to its recommendations, WG3 has been questioning selected industry practitioners on their project experiences. Using an online survey, respondents were asked to reply about a single project. The authors will analyse the data looking for correlations between project characteristics, contractual details and results. The research is currently ongoing and the paper will describe the full details of the methodology and results.

Alan Hodgkinson

Bio

Mr. Hodgkinson graduated with degrees in Eelectrical Engineering and Computer Science from the Massachusetts Institute of Technology and is a member of ITA (Internallional Tunnelling Association) Working Group Three (Contractual Practices). He is a specialist in the automation of business processes, with a focus on project and document management for construction projects. His main interest is developing techniques and technologies for classifying and organising the large quantities of data found in large projects.

Mr. Hodgkinson is founder and general manger of SoftXS GmbH, a Swiss-based partnership offering products and services associated with project and documentation management, primarily for the tunneling industry. SoftXS has supplied systems to major hydropower and metro projects in Europe, Asia and South America.

Prior to founding SoftXS, Mr. Hodgkinson worked for a number of high-tech companies and participated in numerous IT projects, including automation of the Swiss Stock Exchange.

Authors

Seneca D House

Abstract

The District of Columbi'’s Division I Main Pumping Station Diversions, part of the Long Term Control Plan, was designed in a constrained site in close proximity to multiple existing structures, utilities and within a dense populated environment. The challenges of designing and constructing the diversion structures, though many, involved complex geotechnical considerations, ground movement and protection of structures analysis and integral structural and support of excavation systems. As such, DC Water implemented creative contracting methodologies for the procurement of designers and designbuilders to address the challenges of and inherit risks in the design and construction of the large scale near surface structures which interface with CSOs, drop shafts and small diameter tunnels. These design and procurement methods, albeit atypical, allowed for Owner risk mitigation, adaptability to unforeseen challenges arising during construction and the ability to implement repair and rehabilitation on aged infrastructure as necessary.

Seneca D House

Bio

Mr. House functioned as the Structural Engineering Project Engineer, for Parsons Corporation, on the DC Water Division I Main Pump Station Diversions project an integral part of the DC Water CSO Long Term Control Program during the project design phase and is currently the Project Manager for the construction phase of the project. He is experienced in the design of complex water and wastewater projects with expertise in the design management, design and analysis of large underground structures, treatment facilities and piping projects with a focus in using structural engineering technologies for design efficiency. He holds Bachelors of Civil and Masters of Civil/Structural from Florida Atlantic University. Mr. House is a registered Professional Engineer in Florida, Virginia and DC.

Authors

Yves Boissonnas, Marco Bettelini

Abstract

The operational safety of long and very long rail tunnels represents a key issue at all development stages, including design, construction, commissioning and operation. The spectrum of potential threats is very wide and challenging. These issues can only be mastered by means of a combination of a number of safety measures at different levels.

Amberg Engineering is involved in the design and construction of most long and very long rail tunnels in Europe, including in particular Gotthard Base Tunnel (world longest tunnel, to be commissioned in 2016), Lötschberg, Lyon-Tourin and Brenner. The combined experience arising from these tunnels forms an invaluable body of expertise, which shall be summarized in the proposed paper. The proposed paper will focus on the following topics:

ï‚· Review of specific safety issues for long and deep rail tunnels
ï‚· Discussion of common and specific requirements and issues
ï‚· Presentation and discussion of validated solutions
ï‚· Future challenges
ï‚· Recommendations

Yves Boissonnas, Marco Bettelini

Bio

Marco Bettelini looks back on 29 years of experience in ventilation and safety projects. Marco Bettelini was part of major projects like the Gotthard base tunnel, the worl's longest highspeed rail tunnel, the Lyon– Turin base tunnel, a multi-national underwater tunnel project, the Follobanen project in Norway and various other Ventilation and Safety projects around the world.

Currently Marco Bettelini is working on different projects in Brazil, Bulgaria and Switzerland.

Authors

Lee W. Abramson, P.E., Dan McMaster, Andy Thompson, Mike Vitale

Abstract

Performing risk analyses on tunnel projects has become common place and on many projects it is required from an owner or regulatory perspective. After the project is planned, designed and constructed, the data concerning identified risks, assumptions, costs, probabilities and mitigations is generally long forgotten and buried in some file somewhere. A study was performed comparing predicted risks versus actual events on five recently constructed rock tunnel projects in New York, Ohio, Kentucky, Georgia and California. Probabilities and costs for selectively common risks on tunnel projects have been studied and re-evaluated. Conclusions are presented that can guide future projects and the veracity of the tunnel risk analyses performed.

Lee W. Abramson, P.E.

Bio

Lee Abramson possesses extensive experience in various aspects of civil engineering with a specialty in rock and soil geotechnical and tunnel engineering in the United States and abroad. He has worked in the public works consulting and A/E fields as technical lead, expert witness, project manager, principal-in-charge, department head, office manager, and regional manager for over 35 years. He has been a key participant in or leader of a variety of major engineering projects for water resource, wastewater, energy, transit systems, railroads, highways, and other public infrastructure facilities. His direct responsibilities have included all aspects of engineering including planning, analysis, design, construction management, rehabilitation, and inspection. The author of numerous articles and books, he has also assisted in preparing manuals and conducted seminars and courses on tunneling, slope stability, ground improvement, microtunneling, and tunnel rehabilitation.

Authors

Xiaomin You PhD, PE, PMI-RMP

Abstract

The importance of risk management on tunneling and underground construction projects is being well understood among the industry. Risk Management helps the owner, designer and contractor identify and take proactive measures to understand and manage challengers to the project’s successful completion on-time and on-budget. Managing risks is a ‘living’, iterative process that requires a structured, systematic procedure. This paper provides an overview of the existing risk information management tools and outlines the key features required through risk management process. It presents in details an in-house designed risk information management system, which has been successfully employed in several mega transit projects over the last five years, such as Los Angeles Purple Line Extension Project and Regional Connector Project. Experience and lessons learnt from the risk information management system will be discussed at the end of the paper.

Xiaomin You PhD, PE, PMI-RMP

Bio

Xiaomin You is a senior engineer and risk analyst with Parsons Brinckerhoff. She received PhD degree in Civil Engineering from The University of Texas at Austin. She provided engineering services in risk analysis and management for various transit, bridge, and highway projects and had strong skills and experience in structural analysis, tunnel design, numerical modeling and blast protective design. She is a member of American Society of Civil Engineers and a registered Professional Engineer in California and achieved a global credential of PMI's Risk Management Professional.

Authors

Samy Mahdi

Abstract

The Greater Paris project involves the creation of a 200km extension of the existing metro network in the close outskirt of Paris. In 2011, SYSTRA has been awarded the engineering studies of the 20km-long Section 2, in the densely urbanized southeast quarter of the Parisian suburb. In order to both guide the TBM choice and identify and mitigate the risk due to settlement during tunnelling, a great amount of analyses have been carried out to determine the appropriate confinement pressure. The geological context's complexity and the Owner‘s requirements have led to the necessity of using an innovative analysis approach, leveraging through proper calibrations both the numerical modelling analysis’s accuracy and the analytical method's ease of programming and implementation in a Geographical Information System. The GIS platforms became a shared design tool to quickly cross-check the settlement forecasts with the vulnerability of buildings to single out the zones potentially at risk.

Samy Mahdi

Bio

Samy MAHDI is a 5 years experience confirmed Engineer. After being graduated from POLYTECH'PARIS as geotechnical and geophysicist Engineer in 2009, he started his carrier at COYNE & BELLIER (a.k.a. TRACTEBEL ENGINEERING FRANCE) and he specialized in numerical modelling for geotechnical applications. He took part in different projects, including Cairo's Metro and Liefkenshoek tunnels (Belgium) for the contractors, and a major underground storage project for the French national agency for radioactive waste (ANDRA). In late 2011, he joined SYSTRA as responsible for analytical and numerical calculations for geotechnical and hydrogeological complex problems applications and developed analysis tools for tunnel design-related issues. He led the design analyses for the TBM choice and the identification and mitigation of the risk due to tunnelling-induced settlement for major projects such as the Northern extension of Paris Metro Line 14 and Greater Paris Line 15, Section 2.

Authors

Carlo Alessio

Abstract

In 2008, the new Italian code of public works has officially introduced the observational design approach for those works where the complexity and the uncertainties cannot permit to use a fixed-price contract.

The application of that approach to major road and motorway contracts has highlighted the need for defining a comprehensive technical approach and the related contractual forms.

The paper debates on evolution of the observational design application from planning and execution type of contracts to fixed price plus risk coverage contracts, introducing risk analysis as part of tender, design and contracting.

Case histories are presented that focused on relevant aspects of risk analysis, balancing owner’s and designer’s point of view.

Carlo Alessio

Bio

Carlo Alessio, co-founder of the AK Ingegneria Geotecnica Srl, is an engineering geologist with 25 years of experience in the field of tunneling. He has followed numerous tunneling sites in Italy and abroad. In AK he is responsible for all aspects regarding geology, tunneling method selection, observational design, sites design follow-up organization and supervision.

Authors

Michael M Joye

Abstract

Durability design for underground structures is an increasing focus of designers and owners in the underground construction industry. Many owners have expanded their requirements for durability design, with specific requirements for structure lifecycle and designer certification of structural durability. This paper describes current trends and best practices including: Defining the underground structure lifecycle, design methods for underground structure durability, and durability of construction materials.

Criteria to be used for defining end of structure life, and owner’s maintenance responsibilities, are crucial to lifecycle contract requirements. Current practices of several major owners are presented, with a discussion on the associated long term risk of the designer and the builder.

Design methods including prescriptive v. performance design approaches are presented, including code requirements. Current best practices for enhancing the durability of materials used in underground construction are discussed including: low permeability concrete, steel reinforcement concrete cover, the use of steel fiber, and testing for performance verification.

Michael M Joye

Bio

Michael M. Joye, PE, has a BSCE degree from Rensselaer Polytechnic Institute in Troy, NY, and is a licensed professional engineer in New Jersey, New York and Nebraska. He currently works as a Principal Project Manager at Parsons Corporation. He has over 30 years of consulting and design experience in wide-ranging aspects of underground structures engineering, including analysis and design of tunnels and shafts in both soft ground and rock, precast concrete segmental lining design, and cast-in-place concrete lining design. Mr. Joye has been performed durability design of underground structures for Washington’s DC Water’s Anacostia River Tunnel Project, City of Austin’s Waller Creek Tunnel Project, and City of Akron’s Ohio Canal Interceptor Tunnel (Shafts) project.

Authors

John J Reilly

Abstract

The successful management and delivery of megaprojects – within budget, on time, according to expectations is a fundamental requirement. Many projects have been successful, some have not. What lessons can be drawn over the last 50 years that will help us better define successful megaproject management and delivery methods?

This paper will review project outcomes, related to key policies regarding including management organizational structure, contracting methods, risk and other technical policies for a set of underground megaprojects that the author has worked on since 1966. These include the Washington D.C. Metro, Boston Southwest Corridor, Toronto Rapid Transit Expansion Program, LA Metro, London Underground (Jubilee Line, subsequent system-wide PPP initiative) and the Washington State highway megaprojects – including the Alaskan Way tunnel.

Other projects that illustrate successful innovative methods such as the Madrid Metro (delivery), the Sydney Northside Storage tunnel (alliancing) and the Lake Mead tunnel (partnership, risk management) will be included.

John J Reilly

Bio

John Reilly has over 50 years experience in management, strategy, organization, technical review, management oversight, expert panel management, strategic advisory panels, team alignment, partnering, contacting and delivery methods, risk management and probabilistic cost/schedule analysis for large, complex infrastructure projects including tunnels, metro systems, highways and bridges. He has led several Expert Review Panels and Strategic/Technical Advisory Teams for recent megaprojects. Previously, he was President of the American Underground Construction Association and Chair of two International Tunneling Association Working Groups – 13 (Benefits of Underground Structures) and 20 (Urban Problems, Underground Solutions).

He is a graduate of the University of Sydney (BE Honors) & University of California Berkeley (MS)

Authors

Angus Sean Maxwell

Abstract

An expert system is a system which modifies its behaviour and results based on analysis of learnt data. In the context of tunnelling this relates to the use of prior data to predict future performance. All tunnelling is observational and this process is normally undertaken by staff who make use of prior experience and expertise to judge tunnelling parameters in order to optimise machine behaviour and minimise unfavourable consequences. The rapid pace of tunnel projects precludes the ability to cross correlate the many revealed parameters and so computational methods have been developed to aid the processing. The paper describes a new operating system for tunnel construction MISSIONOS and describes how it has been used for risk and cost control on a number of Asian projects.

Angus Sean Maxwell

Bio

Angus Maxwell is the founding Director of Maxwell Geosystems Ltd. providing instrumentation management systems and geotechnical consultancy services to over USD25 billion of construction in Asia since 2004. He joined Mott MacDonald in 1990 and between 1993 and 1995 he was data management leader for High Speed Rail I from Folkestone to St Pancras. At the time this was the UKs largest GI database for a single construction project. From 1995 to 2001 he was Resident Geotechnical Engineer on the Strategic Sewage Disposal Scheme in Hong Kong and implemented the Tunnel Data Management System (TDMS) before moving to geotechnical specialist Coffey Geosciences as Hong Kong Manager. He has expertise across a variety of practical geotechnical and engineering disciplines. He is the former Chairman of the Association of Geotechnical Specialists Hong Kong and a current committee member of the Tunnelling and Underground Construction Society Singapore.

Authors

Khaled Elnabolsy

Abstract

The Regional Municipality of York has commenced the Bathurst Street and Teston Road Watermains project which includes a 680m long tunnel to install a 1050mm diameter watermain. This paper will present a client, engineer, and contractor discussion of the design, tender preparation, and construction phases of this project.

On York Region's Bathurst Street and Teston Road Watermains project, GHD proposed that a 680m long section of a 1050mm watermain to be constructed using a double pass system with Microtunnelling and pipe jacking (1800mm diameter) mainly to provide a cost effective solution that facilitates crossings of environmentally sensitive areas.

CRS tunnelling proposed through the general contractor, Memme Construction, the use of the Earth Pressure Balance Method with segmental lining (3000mm diameter) due to multiple reasons including resources availability and construction risk mitigation.

This paper will present GHD's assessment of the feasibility of the microtunnelling and pipe jacking construction method and provide a discussion on the tendering of the project. The paper will also present CRS's proposal to use the alternative method of EBP and segmental lining, and the decision making process of approving the alternative method. The construction phase outcomes of using the EPB and segmental lining method will also be presented.

Khaled Elnabolsy

Bio

Khaled graduated from the University of Waterloo with a bachelor degree in Civil Engineering. He has gained over 6 years of construction and design experience in tunnelling and linear infrastructure. He worked on some of the Greater Toronto Area's high profile tunnelling projects including the Southeast Collector Trunk Sewer project and the Eglinton Subway Tunnel Project.

Authors

Faruk Oksuz, PE; Cary Hirner, PE

Abstract

Coupled with shortage of resources, delays, political pressures, and other obstacles in procurement and negotiation processes, the owners, engineers, and contractors are also looking for creative ways to optimize the contract packaging strategies for efficient and successful project delivery. Large tunnels engineering and construction require alternative contracting strategies to address management, risk, quality, operability, performance, schedule and delivery concerns. This paper compiles an array of decision making criteria and tools and presents an unbiased and balanced evaluation and ranking system in procurement of engineering and construction services for large tunneling. We define pro's and con's of traditional design-bid-build vs. alternative delivery including design-build, design-build-operate-maintain, construction management at-risk, owners engineering, and public-private-partnerships (P3) with lessons-learned and case examples. Specifically, the owners' viewpoints are discussed on large tunnel programs.

Faruk Oksuz, PE

Bio

Faruk Oksuz, PE, is the Vice President and Director of Integrated Heavy Civil Infrastructure Systems engineering and construction management global business lines at Black & Veatch. With nearly 28 years of experience, he provides technical direction and mentoring for risk management, technology, innovation, management and execution for large tunnels, dams, intakes, gates, pump station facilities around the globe, and most notably involved with Chicago's TARP, Milwaukee's Northwest Side, Austin's Jollyville, and Singapore's DTSS Phase 2 tunnels. He has degrees in Mining Engineering and Mechanical Engineering & Energy Processes from the Istanbul Technical University and Southern Illinois University.

Authors

Gerald Bauer, PE; Steve Courtland

Abstract

The City of Ottawa's Combined Sewage Storage Tunnel consists of two interconnected tunnels totaling 6.2 km with a finished diameter of 3 m including a number of access shafts and hydraulic structures which connect to some of the City's most critical sewers. This tunnel is being built at a depth of 15 to 30m below ground in the downtown core adjacent to, and crossing below, the Light Rail Tunnel (LRT), which introduces additional considerations for the project in terms of sequencing. The City of Ottawa embarked on a unique procurement process to address the risks involved with a large tunnel project and those associated with tunneling below downtown adjacent to UNESCO World Heritage Sites and connecting to live critical sewers. This paper describes the unique procurement approach the City of Ottawa used to address the contractual risk mitigation measures developed to provide the best value for the project. Specific features include Market Sounding, using a Fairness Commissioner, Contractor PreQualification and Risk Mitigation Measures in the Tender documents.

Gerald Bauer, PE

Bio

Mr. Bauer has over 33 years of experience in the fields of municipal and environmental engineering, with the last 25 years focusing on trenchless technologies from rehabilitation to new installations. His depth of experience in (trenchless technology) methods ranges from evaluation, planning, assessments and design, to site services during construction. Mr. Bauer has provided advisory services for Value Engineering sessions on large infrastructure rehabilitation projects and to the National Research Council of Canada developing guidelines for condition assessment and rehabilitation of large diameter sewers, and the development of best practices on the evaluation and assessment of sewers for their National Guide on Sustainable Infrastructure. He has completed a number of tunnel installations ranging in size and length through difficult surface and ground conditions. He is the design manager and construction manager of the City of Ottawa's Combined Sewage Storage Tunnel. Gerald is a member of the NASTT and is currently the Secretary for the Great Lakes Saint Lawrence and Atlantic Chapter.

Authors

Piergiorgio Grasso, Moreno Pescara, Luca Soldo

Abstract

Risk Management in tunnelling is more important today than it was a few years ago, also considering the increasing requests in term of safety, environmental and socio-economic sustainability coming from citizens, owners, lenders and insurers. More, the Risk Management philosophy is intended not solely on risk avoidance and mitigation, but also as a means to value creation, ameliorating the overall project. Given the strategic implications of Risk Management, the authors have intended to give in the present paper a thorough overview of the references and experiences in current practices, together with the developments, possible and necessary, that might have a key role in implementing Risk Management effectively within the project life, particularly considering the design and construction phases. The analysis considers the available best methodological and scientific approaches, the normative and contractual references, the innovations induced from the new digital tools.

Piergiorgio Grasso

Bio

Piergiorgio Grasso is the founder, Principal Engineer and President of Geodata, an international multidisciplinary engineering firm. Employing a staff of over 400 professionals, with offices in four continents, Geodata provides a wide range of design services of infrastructures for transportation, water supply, utilities and services and land regeneration & development.

As Principal Engineer of Geodata, Mr. Grasso has been responsible for the design and construction of over 3,000 km of tunnels and underground facilities, for a wide range of uses, worldwide.

Mr. Grasso has been responsible for the successful development of a number of innovative design methods and tunnelling technologies/procedures. For his authoritative experience, he is frequently Expert member of international Panels. He is First Vice President of ITA (where he is also Animateur for Working Group 17 'Long Tunnels at Great Depth'). He published over 200 articles and 2 books on Geo-Engineeering and Tunnelling.

Authors

Tao Jiang

Abstract

The City of Atlanta is converting the over-a-century-old Bellwood Quarry into a 2.4 billion-gallon raw water storage facility as the only backup water supply for the entire city. A water conveyance system, consisting of a deep hard rock tunnel with multiple deep pump stations and dropshafts, will be constructed to transport water in between the facilities. The project has two phases with Phase I tunnel approximately 2,100m long, 120m deep, and 4m in bore diameter. The tunnel will be bored from a portal at the Quarry and concrete lined. The Phase II tunnel is approximately 6,000m of similar depth and size. Modified contact grouting will be applied to control water infiltration and exfiltration. Comprehensive computational fluid dynamic (CFD) analyses were performed for the system to assist the design. The City chose Construction Management At-Risk (CMAR) as the project delivery method, an innovative contracting method fairly new to the tunnel industry.

Tao Jiang

Bio

Tao Jiang is the tunneling practice design manager with Stantec. He has been the tunnel design lead for numerous wastewater/water and transportation tunnels in both hard rock and soft ground using TBM, sequential excavation, and cut and cover methods. His expertise includes initial ground support, sprayed concrete lining, cast-in-place concrete lining, precast concrete segmental lining, and seismic design for tunnels. Tao obtained his Ph.D. degree in Geotechnical Engineering from Clemson University in 2002.

Don Del Nero is Stantec’s Practice Leader for tunneling and trenchless technology. He has over 24 years of experience with the planning, studies, design, and construction management of tunnels and trenchless engineering. His experience covers over 40 miles of tunnel and trenchless installations worth over $1.3 Billion in construction value. He has direct knowledge of all trenchless technologies currently practiced. Don Obtained his Master Degree in Geotechnical Engineering from Syracuse University in 1994.

Authors

Jim D. Nickerson, Marc Jensen, Erika Moonin

Abstract

This paper will explain how the Contractor and Owner avoided a contractual dispute involving characterization, impacts, and final remedy for challenging ground conditions encountered during drill and blast excavation of the starter tunnel required for launch of the TBM. During excavation more than 600 feet underground, the Design-Builder encountered a large complex fault zone subject to 14 + bar of water pressure. Successive ground inflows from the fault complex over a six-month period presented significant technical and partnership challenges for the team and ultimately delayed the project by nearly one year. This paper will discuss how the Contractor, Owner, and their respective consultants worked together to address these challenges, make decisions, and ultimately move the project to successful completion.

Jim D. Nickerson

Bio

Jim Nickerson is currently the Project Manager of the Lake Mead Intake No. 3 Project he has over 30 years of service in the tunnel construction industry, building multiple Projects in the USA and overseas. He has a wide-range of experience in small and large diameter underground projects, in soft ground and rock tunneling.

Authors

Erika Moonin

Abstract

Due to severe drought in the region, the Southern Nevada Water Authority has been constructing a new intake system to ensure water supply to the Las Vegas communities. In 2015, design began on the Low Lake Level Pumping Station which includes a 159 meter deep shaft, a large underground chamber, and 34 each 152 meter deep 2 meter diameter drilled well shafts to be excavated in highly faulted and fractured ground. The Construction Manager at Risk (CMAR) delivery method was chosen for this project to involve the contractor in the design process to address the significant challenges and risks anticipated on this $650 Million USD project. This paper will explain the CMAR selection process, the CMAR involvement during design and discuss how the owner, engineer, and CMAR collaborated to evaluate the risks and develop as a team the design features, underground construction methods, geotechnical baseline report, and contract terms and conditions.

Erika Moonin

Bio

Authors

Brian T Hamilton

Abstract

The Eglinton-Crosstown Light Rail Transit line is a 19-kilometre corridor with a 10-kilometre underground portion currently being constructed by Metrolinx in Toronto through a densely populated urban environment. Tunneling works are being completed through two separate design-bid-build contracts that include consideration for a phased handover to a follow on contractor who will take ownership of the tunnels, including warranties, and will complete the stations and remainder of the system through a PPP delivery model including maintenance of the system for 30 years. Warranty provisions, settlement apportionment, tunnel leakage, potential delays and conflicts between contractors are just some of the risks the team managing tunnel contract integration had to consider when developing the PPP contract. This paper will present an overview of how these risks were assessed and allocated through the contracts and the strategies adopted to minimize risks to Metrolinx while ensuring successful procurement was maintained.

Brian T Hamilton

Bio

Brian Hamilton is a Senior Project Manager with more than 28 years of experience in project management, design, and construction of civil infrastructure projects, including some of the largest, and logistically complex infrastructure projects in North America. Mr. Hamilton has extensive project management experience on projects delivered by a variety of contract delivery methods, ranging from traditional design-bid-build through to alternative delivery methods.

Mr. Hamilton has authored several professional papers on tunnel design and construction. He received a BSc in Geology from the University of Illinois in Urbana and an MSc in Geological Engineering from the South Dakota School of Mines and Technology in Rapid City. He is a registered professional geologist in Minnesota.

Authors

Don E Del Nero, Anil Dean, and Julian Prada

Abstract

In the age of austerity budgets and compressed construction schedules owners are looking beyond conventional design-bid-build contract delivery for heavy civil tunneling works. Innovations in contract delivery including design-build and public-private-partnerships are now fairly well established and accepted by the majority of the tunneling community at large. Yet there remains a demand for unique or innovative contracting practices within each major delivery model to address on-going project uncertainties, risk tolerance and economic factors. This demand has resulted in the evolution of several unique contracting practices and contract clauses such as risk/reward payments, a fairness commissioner, differing site condition waivers, no ground risk contracts, commercially confidential pre-bid and post-bid contractor meetings, and an optional clause for dispute review board use. Multiple project case histories from the United States and Canada will be referenced to explore the benefits or highlight the downsides of the subject contracting practices.

Don E Del Nero

Bio

Don Del Nero is the Tunneling and Trenchless Engineering Practice Leader for Stantec with over 26 years of experience including planning, studies, design, and construction management primarily in the areas of tunneling and trenchless engineering. He is on the Board of Directors for the North American Society for Trenchless Technology and is an instructor for NASTT and the Colorado School of Mines. Don has worked on over 70 projects, over 50 miles of tunnel and trenchless installations, worth over $2 Billion in construction value and often guides agencies on underground risk management, means and methods, and contracting strategies.

Authors

Jonathan Taylor, Michael Joye, and Pooyan Asadollahi

Abstract

In recent years, the tunneling industry in North America has all but abandoned traditional design bid build procurement methods for large tunnel projects, as owners and their consultants have rushed to embrace the promise of rapid, inexpensive, risk free construction delivered by alternate contracting practices. The primary procurement methods have included a variety of design build (DB) and public private partnership (P3) creations. This paper evaluates the benefits of alternate contracting methods, and compares the features of several different projects or programs, consisting of highway, transit and utility tunnels, that have been bid in this way in the last ten years. Different approaches to developing the tunnel baseline conditions and managing technical collaboration prior to bid are discussed from the contractor's and owner's perspectives. Finally, the advantages and disadvantages of the different systems employed in the various procurements are also described based on the authors' experience.

Jonathan Taylor

Bio

Jonathan Taylor is an accomplished professional engineer and project manager with more than 30 years of experience involving geotechnical engineering for diverse projects, such as airports, tunnels, dams, roadways, railroads, and industrial plants. Throughout his career, he has designed deep foundations, underground structures, ground improvement systems, and retaining walls. Jonathan also has extensive experience preparing construction contract documents and cost estimates, and he has proven to be an effective project manager.

Authors

Martin P. Schroeder

Abstract

Challenges have emerged as subway systems age and as new tunnels are bored in congested corridors or in high risk environments. To help public transportation agencies address tunneling challenges, APTA has convened numerous independent industry peer reviews composed of top experts in their fields to come together and provide recommendations and solutions. Although solutions are usually technically based, it is common to experience strong disagreements between stakeholders requiring a special effort to reach a mutually satisfactory position. This paper provides case histories of peer reviews that include topics such as boring through toxic soils, boring underneath existing tunnels, retrofit of tunnel ventilation systems, and mitigation of water intrusion. Peer reviews are applicable to all tunnel projects worldwide. The paper will highlight the conditions of these challenges, peer review recommendations, steps taken to reach agreement, and the major successes that resulted, some of which led to major changes and new legislation.

Martin P. Schroeder

Bio

Martin Schroeder is the Chief Technology Officer for the American Public Transportation Association with responsibility for technical and operational programs related to all modes of rail and bus transit systems. Mr. Schroeder establishes technical research efforts for the organization and leads key committees with responsibility for engineering research and federal rule making. Mr. Schroeder is also a key facilitator of extensive peer reviews on behalf of the industry focusing on challenges and risks in tunneling, safety, program management, vehicle engineering and organizational structure. He also serves as chairman of the American Society of Mechanical Engineers committee on the standardization of railcar structural safety design, and is chairman of the U.S. working group for the International Standards Organization in Public Transportation. As a registered professional engineer and formally an assistant professor of mechanical engineering at Western Michigan University, Mr. Schroeder is also a trained mediator in conflict resolution.

Authors

Eric Prantil

Abstract

Tunneling through an urban environment carries many inherent risks to the immediate local infrastructure and subsequently to the project stakeholders. On the CQ031 Contract of the East Side Access Project in Queens, New York, twin 22.5' diameter Herrenknecht Slurry TBMs were mined within close proximity to many infrastructure assets, with cover of less than half a shield diameter at times. Multiple public bridges and critical railroad infrastructure including catenary poles and signal towers supporting the busiest rail interlocking in the United States required underpinning systems. The support program for these structures was refined over the course of the four tunnel drives. It is the intent of this paper to show how the interaction between the temporary structures, instrumentation monitoring plan, and risk assessment program melded to provide a system which the owner, contractor, and designer relied on as a tool to ensure the project success without impacting the public surroundings.

Eric Prantil

Bio

Eric Prantil has five years experience in tunneling and underground design and construction. His project exposure includes experience in tunnel and shaft design, slurry tunneling methods, and SEM construction. He has also been involved in the construction management of large scale tunneling projects. Mr. Prantil has a B.S. and M.S in Civil Engineering from the NYU Polytechnic School of Engineering.

Authors

Dean R. Brox

Abstract

The design and functional requirements of rock traps for hydropower pressure tunnels continues to be not fully understood and appreciated in the hydropower industry. The poor performance of a rock trap can have a severe impact on hydropower generation due to damage caused to turbine runners, and therefore increased operating costs, from material transport commonly associated plucking and scouring of an unlined hydropower tunnel. Empirical relationships of material transport developed in the 1960's and 1970's provide a firsthand check on the risk of material transport of significant sizes in relation to the mean tunnel flow velocity. Computational fluid dynamic models provide a means for relatively simple and quick evaluation of turbulence and thresholds for material mobility for a given rock trap design whereby turbulent kinetic energy can be adopted as a key indicator and related to the start of bedload and suspended load transport. The results of such analyses provide key input for the design of rock traps to limit or prevent damage to turbine runners. The paper will discuss the typical design and functional requirements for rock traps for hydropower pressure tunnels and will present design examples with the results of computational fluid dynamic analyses.

Dean R. Brox

Bio

Dean graduated from the University of British Columbia in Geological Engineering and holds a Master’s degree in Engineering Rock Mechanics from Imperial College, University of London.

Dean has 30 years of experience in the design and construction of over 1000 km of major tunneling and underground infrastructure projects for Civil, Hydropower, and Mining projects. He has worked on tunneling projects in Argentina, Canada, Chile, Hong Kong, Malaysia, Panama, Peru, Philippines, South Africa, Switzerland, and Taiwan.

Dean's specialist experience for underground projects includes risk and constructability assessments along with the use of tunnel boring machines for long and deep tunnels subjected to overstressing.

Authors

Ashok Kumar Chadha, R.K. Chauhan, M.P. Singh, Dr. Umakant Sharma

Abstract

Rampur Hydroelectric Project (412 MW) is recently commissioned project of SJVN Limited India and successfully works on principle of tandem operation with already commissioned Nathpa Jhakri Hydro Power Station (1500 MW). The main objective in case of Tunnels constructed especially for hydro projects, which carry enormous quantum of water is that, it should not leak. Moreover, the tunnels which are part of water conductor system should resist the inflow of water from the surrounding ground in order to avoid draining of natural water sources and lowering of existing groundwater levels. Lowering of water table may result in subsidence and damage to existing surface structures, loss of capacity of drinking water schemes and in some cases even catastrophic sliding of landmass. Grouting and pre-grouting in tunnels serve three different purposes i.e., Stabilization, Strengthening and sealing of the rock mass around tunnels to avoid leakage of water from tunnels. In present paper, results of grouting methodology adopted during final construction stage of RHEP (412 MW) along with the introspection of Water Pressure Tests conducted for determination of the efficacy of grouting were elaborately presented. The process, of contact and consolidation grouting which is respectively followed by water pressure tests along entire reach of HRT (15.177 Km long) were also addressed in detail. Pertaining to the results of water percolation tests (before and after consolidation grouting), it was also attempted to categorize the behaviour of different rock mass classes/ conditions in reference to different quantum of grout intake and corresponding Lugeon values. Importance of planned and dedicated successful grouting procedure adopted in hydropower project at RHEP is also emphasized.

Ashok Kumar Chadha

Bio

The Author, Ashok Kumar Chadha, is Master of Science in Geology (MSc) from then Rajasthan University, Department of Geology, Udaipur and is at present working as General Manager (Geology) in SJVN Ltd., a Joint venture of Govt. of India and Govt. of Himachal Pradesh ( "Mini Ratna" and Schedule 'A' PSU) currently posted at its Corporate Office at Shimla. He has a total work experience of 36 years, out of which 31 years are in the Planning,Investigation and,Construction of Hydroelectric Projects in various parts of India& abroad and remaining 5 years in Mineral Exploration and, Teaching in the University.

The Author has worked for 12 years during construction of prestigious 1500 MW Nathpa-Jhakri Hydroelectric Project, 67.5 m high dam, 27.4 Km long HRT and an underground Power House [222(L)x20(W)x49(H)] in districts of Kinnaur and Shimla of Himachal Pradesh, India in complex Himalayan Geology. Further he has worked for 6 years during construction of 125m high dam and 9 Km long HRT of Chamera Hydroelectric Project Sage-I (520 MW) of NHPC Ltd, on the river Ravi in Chamba district of Himachal Pradesh, India, besides Investigation work of 300 MW Chamera Hydroelectric Project Stage- II of NHPC Ltd for 3 years, on river Ravi in Chamba district of Himachal Pradesh, India. At present the Author is posted at Headquarters for last 10 years and is involved in Conceiving New Hydroelectric Projects, Planning their Investigations, Preparation and Clearance of Detailed Project Reports (Geology related) of these projects in Himalayan rocks.

The Author has 5 numbers of publications to his name on geological aspects of Nathpa-Jhakri HEP and presented them in various Conferences.

Attended various International, National conferences, seminars and symposium etc. in India.

Authors

Wenhao Xiao, Yong Yuan, Luc Taerwe

Abstract

The static shear stiffness of an immersion joint subjected to a compression and shear force is investigated by experiments in a unique test set-up. To explore the performance of the immersion joint, the compression-shear loads, which are applied on a scaled specimen (3800mm x 1250mm x 1150mm) according to a specific test protocol, are determined on the basis of real design situation. In this test, the main focus is on the steel shear keys and rubber sealing. For the applied loading schemes, different levels of axial forces, corresponding to the water depths of the joints, are considered as well as the changing amplitudes of the shear forces. The force-displacement curve is obtained and the hysteresis is observed during the whole test. Based on these results, the static shear stiffness is calculated and the results indicate that the static shear stiffness of the joint increases linearly with the axial force. Moreover, it is found that the rubber sealing has a significant influence on the shear behavior of the joint.

Wenhao Xiao

Bio

Wenhao Xiao is a PhD candidate in Ghent University (Belgium) supervised by Prof. Taerwe. He earned his master and bachelor degree in Tongji University (China, 2015) and Hunan University (China, 2012) respectively. His research is situated in mechanical behavior of immersion joint.

Authors

Yoichi Shimada

Abstract

Temporary earth-retaining walls used in cut & cover method for the construction of tunnels were installed vertically in the past; however, for excavation up to depths greater than about 4 m, shoring such as struts and king posts was generally employed to ensure the stability of the walls. In order to do away with the shoring expecting improvement of efficiency of the work, new design and construction methods were studied with a focus on the effectiveness of inclined earth-retaining walls, leading to the development of the Inclined-Braceless Excavation Support (IBES) that can be applied to deep cut & cover excavation work. This construction method was successfully applied in 6 construction sites in Japan in recent years. The paper introduces further developed IBES with inclined buttress applicable to deep excavation work with high groundwater table and presents design methods based on model experiments, 3D-FEM analysis, and monitoring records at construction sites.

Yoichi Shimada

Bio

The author was involved with numerous construction projects both in Japan and overseas for 25 years as a Design Manager working for Obayashi Corporation, one of the foremost general contractors in Japan. These projects were primarily construction works for underground structures such as LNG (Liquefied Natural Gas) underground tanks, railway and road tunnels, and subway stations. The author designed structures and conducted design supervision during construction.

In recent years, he has been providing technical guidance on geotechnical subjects, foundations, and underground structures for domestic and overseas projects. As the leader of a research and development team, he has developed a new earth-retaining construction method for open cut tunnels. He established the design method for the construction method introduced in this paper through centrifugal model experiments, FEM analyses, site measurements during construction, etc., for improving the workability of construction and reducing the cost and construction period.

Authors

Remo Grandori

Abstract

Back in 2010 SELI developed an advanced design for its Double Shield Universal (DSU) TBM for the excavation of the 14 km long 6 m diameter Kishanganga tunnel in the Himalaya region. This TBM was a great success been the only TBM having completed a segmental lined tunnel under the Himalaya, and on schedule.

Now, 5 years later, SELI Overseas, in cooperation with Terratec and Misthubishi, raises the bar of rock TBM technology by designing a newly 10 m diameter DSU TBM to excavate the 12 km long Vishnugad tunnel in Uttarakhand (India)

All design features that leaded to the success of the Kishangnaga TBM have been taken to the extreme for this new TBM that will bore under high covers in the difficult geologies of the Himalaya. The article describe the special design features of this large diameter TBM and of the precast lining installed along the tunnel.

Remo Grandori

Bio

Born in 1960 has graduated in 1984 in Mechanical Engineering with a thesis on mechanical excavation by TBM.

Since 1984 is working in SELI, starting as TBM engineer following different TBM sites all over the world and at present he is CEO of SELI Overseas,. During its 30 years in SELI he has directed and supervised over 100 TBM projects and 700 km of tunnel excavated. Just to mention few of them: Whanjazhai Yellow River Diversion Project (China), Brenner tunnel (Italy), Kishnanganga (India), Metro projects in Turin, Rome, Vancouver, Caracas, S. Paolo, Oporto, Athens, Tessaloniki, New York.

During the same period Mr. Grandori has also acted as Consultant for several public and private Clients for the design and execution of major tunnel projects. He has developed new TBM type/designs (Double Shield Universal TBMs, Compact TBM systems, Fine Injection EPB-TBMs, Dual mode EPB/DSU TBM ) as well high performances back-up systems.

Authors

Andrea Antiga

Abstract

The field of underground works is very lively, in recent years there has been the development of innovative approaches to design and construction. One of the most debated topics is the comparison between a design approach that, in difficult ground conditions, make use of a partialization, also in multiple parts, of the excavation face and the one that prefers a full-face excavation using systems of face stabilization.

This debate is part of a more general juxtaposition between those who claim the supremacy of NATM method, or other sequential excavation methods related to it, and those who express criticism of it and propose innovative alternative systems among all is the full-face method ADECO.

We will present some insights in order to provide a contribution to this debate. We analyze the static and technological aspects of the topic by comparing the two approaches also with the aid of numerical and analytical calculations.

Andrea Antiga

Bio

Andrea Antiga gained 25 years of experience in the field of tunnels. He participated in the projects of several underground works (more than 110 tunnels for an overall length of nearly 300 km, 6 sections of underground lines and 21 underground stations). He was employed at ROCKSOIL (1991-1996) as Project Manager; he participated in the design of difficult tunnels that have become, thereafter, reference for the method of construction ADECO. He has worked as free-lance since 1996.

Since 2000 he has been collaborating with SOIL of which is Partner and Technical Director. He has drawn the guidelines for the design of tunnels on behalf of SPEA/SOCIETÀ AUTOSTRADE.

He was Responsible for PARSONS, in 2011, for the Final Design Audit for underground works regarding railway and roadway connections (2,500 EUR million) within the Strait of Messina Bridge project. He is author of various publications and courses in the underground works sector.

Authors

Stefan Lemke, Dr. Martin Eckl, Dr. Martin Londschien

Abstract

Tunnels are built with a design life expectancy of over 100 years. One key component of such a design is the waterproofing system, which must reliably fulfil its function during the whole service life time of the tunnel structure. This paper deals with the determination of test criteria for the durability assessment of geosynthetic products in tunnel sealing systems. The objective of this research program is to derive suitable exposure conditions and criteria for a practical testing procedure with regard to service lifetimes of up to 100 years. To verify the results of the new test procedure the material properties of geosynthetic products samples removed from older tunnels are investigated. Based on the presented results of the still ongoing research program some preliminary conclusion regarding the updating of regulations for tunnel sealing systems are given.

Stefan Lemke

Bio

Holding both Master's degrees in Engineering and in Executive Business Administration Stefan is a chartered civil engineer with over fifteen years experience in sales and management of major infrastructure projects, in particular waterproofing. Stefan's experience has included holding senior positions in the construction of tunnels in Europe and Asia, in particular the Hallandsås tunnel in Sweden and the Taiwan High Speed Rail project.

Stefan is an International/Corporate Market Field Manager at Sika Services AG for infrastructure waterproofing projects and heads the Key Owner Management at Sika.

Stefan has previously acted in various industry working groups and standardization committees for tunnel waterproofing and drainage design in Germany and Austria and is currently a member of the working group 5.1 (German Geotechnical Society).

Authors

Juan M Mayoral

Abstract

A numerical study was undertaken to establish a more rational design criteria for the primary and secondary lining of tunnels built in cemented fine-grained stiff soils, based on the load taken by each support element. Typical tunnel covers, geometries and soil properties were used in the parametric study. Series of tridimensional finite difference models, developed with the program FLAC3D, were used to simulate the tunnel construction to compute the ground settlements and internal forces and displacements induced at the primary and secondary tunnel linings. Interaction diagrams were used to study the lining performance. Several advancement lengths were evaluated, as well as primary and secondary lining thicknesses. Three key construction stages were identified and analysed: 1) when the tunnel has no lining, 2) when only the primary lining is working, and 3) when the secondary lining is placed. From the results gathered in this study, a practice-oriented design approach was proposed.

Juan M Mayoral

Bio

Civil and Geotechnical Earthquake Engineer with 22 years of experience in geotechnical engineering and earthquake engineering projects. Dr. Mayoral areas of expertise are numerical modeling of geomaterials, earthquake engineering, seismology, and instrumentation. His representative experience ranges from conventional geotechnical engineering projects to highly specialized analyses of seismic soil-structure interaction and other earthquake engineering problems conducted for projects all around the world. Doctor Mayoral has participated on geotechnical studies, foundation design, soil exploration and laboratory testing, and performed geotechnical field work supervision. In addition he has performed dynamic response analyses of earth dams, natural soil deposits and manmade fills, including liquefaction risk assessment. In the area of seismic soil-structure interaction, Dr. Mayoral has analyzed foundation systems of LNG tanks, buildings, bridges and tunnels. He is a professor at the Institute of Engineering, at UNAM.

Authors

Benno K Ring

Abstract

Cross-passage-design is among the most difficult tasks when designing TBM-tunnels. At one time the bedding of the lining disappears due to excavation, at another the ring-structure is interrupted when parts of the lining are removed for the opening. The trick is to transfer the loads around the opening into areas still supported by ground.

Modern solutions bearing the loads within the segments have become popular. Shear-elements in the ring-joints transfer loads from one segmental ring to its neighbour. Typical elements and their respectively transferred forces are:

· Cam & pocket, with gap or direct coupling --> radial forces.
· Shear-keys (core drilling over the ring-joint) --> normal forces.
· Dowels, steel/synthetics --> normal and radial forces.


The solutions differ in stiffness and strength, advantages and disadvantages, and have limits in stabilizing the lining at cross-passages. With finite-element-analyses for an opening of one segmental ring, different solutions are compared for differing ground conditions.

Benno K Ring

Bio

Authors

Apostolos Vrakas, G. Anagnostou

Abstract

The routinely made small strain assumption in tunnel analyses remains sufficient as long as convergences do not exceed 10%. This condition is fulfilled in the great majority of tunnelling projects. Under extreme squeezing conditions, however, the small strain assumption leads to severe prediction errors. Herein, we show how large deformations can be accounted for in a very simple way, based upon the results of routine small strain analyses. A simple equation is presented, which allows correcting the results of small strain analyses, thus removing the need for large strain numerical analyses, at least at the preliminary design stage. The practical importance of taking large strains into consideration in tunnel analysis is illustrated by means of three case studies of tunnelling through heavily squeezing ground: the Gotthard base tunnel, the Yacambú-Quibor water transmission tunnel and the Lyon-Turin base tunnel.

Apostolos Vrakas

Bio

Doctoral student in the field of Tunnelling under the supervision of Prof. Dr. G. Anagnostou. Research project: 'Analysis of Large Deformation Problems in Tunnelling Considering Geometric Nonlinearities', funded by the Swiss National Science Foundation under Project No. 200021_153433.

Authors

Peter Graham Jackson, Bo Tvede-Jensen, Tamas Bodri, Vincenzo Zeuli

Abstract

The project involves the construction of a main water collection tunnel 9.5 km long and with an excavation diameter of 4.5 metres, as well as the construction of 21 access shafts of various diameters and depths. The excavation of the tunnel will involve two TBM. The segmental lining of bored tunnel is designed as steel fibre reinforced concrete (SFRC). The steel fibres will be made of carbon, colddrawn steel wires. The grade of steel fibre reinforced concrete is classified as a C55 4c in accordance with CEB-FIB Model Code 2010. The rings close to the adits (special segments) have been designed as traditional stainless steel reinforcement.

The extreme environmental exposure combined with the required service life of 100 years for the main concrete structures, calls for the highest attention regarding design, structural detailing, material composition, waterproofing, construction and maintenance and sets some very demanding requirements to the design and construction.

Peter Graham Jackson, Bo Tvede-Jensen, Tamas Bodri, Vincenzo Zeuli

Bio

Peter Graham Jackson Mr. Jackson a Project Director in COWI's Bridge, Tunnel and Marine Structures Division. He has played a major role in a number of large tunnel projects, these include the STEP project in Abu Dhabi and the Busan-Geoje Fixed Link in Korea, Malmö Citytunnel, Copenhagen Metro and the Jubilee Line Extension.

Bo Tvede-Jensen Mr. Bo Tvede-Jensen is a senior tunnel engineer with design and project management experience. He has successfully worked in Germany, Denmark, South Korea and United Arab Emirates. Currently he is working as Head of Section in the Tunnel & Underground Structures Department for COWI in Copenhagen.

Vincenzo Zeuli Mr. Zeuli is a Senior Tunnel Engineer in COWI's Bridge, Tunnel and Marine Structures Division with design and project management experience. His career has been linked with major Italian project (Underground, Road Tunnel, Metro).

Tamas Bodri Mr. Bodri is COWI's tunnelling specialist His work focused on the design and construction of large-scale infrastructure projects, such as London's Victoria Station Upgrade, the Airport Link Tunnel Project in Brisbane and Copenhagen's new metro line, Cityringen. He is currently based in Qatar, as the Designer's Representative of the Abu Hamour Surface and Groundwater Drainage Tunnel project.

Authors

Daniel Borbely, Tamas Megyeri, Vera Szanto, Elod Kandi

Abstract

Upon completion, the Bàtaapàti deep underground radioactive waste repository complex (NRHT) will provide safe storage for low and medium-level radioactive waste from the Nuclear Power Plant of Paks, Hungary. The waste emplacement is in progress and one of the main concerns related to the development is the successful demonstration of a feasible permanent repository closure. Several clay filled fault zones were penetrated with the access tunnels that are to be plugged. Detailed mechanical analysis and numerical modelling of the tunnel constructed through a fault zone is presented here in order to gain a better understanding of the rockmass and rock support behaviour. A demonstration chamber for a full scale sealing test was constructed in early 2015, providing an opportunity to compare the results of the analysis to actual monitoring results in order to validate the calculations.

Daniel Borbely

Bio

Daniel Borbely is currently working with the Tunnels Group in the Vancouver Office. His PhD dissertation is under completion on numerical modelling of fractured granitic rock masses. He has worked on diverse tunneling projects as a designer, and has been responsible for various tasks in the design process including rock support design, geotechnical modelling, and rock mass classification. His field experience consists of rock mass classifications for open pit mines (including mapping, measuring, and statistically analyzing joint sets) and visiting tunneling projects in Hungary and Switzerland. His laboratory experience consists of standard lab tests of rock samples and logging of core samples of soils. His design experience consist of geotechnical and structural design of shafts, tender design of immerse tube tunnel, conceptual design of the engineering barrier in radioactive waste repository, detailed design and numerical modelling of tunnels under highly populated urban areas, and open pit mine design.

Authors

Yasuo Sawamura

Abstract

Three-hinge arch culvert is a new type of open-cut tunnel which include hinges in the main body. Because there are hinges, the culvert actively utilizes subgrade reactions by permitting deformation. In addition, in the design of the culvert, the coefficients of the earth pressure and the ground spring are modified depending on the height of the embankment.

In this study, large-scale model experiments targeted for Three-hinge arch culvert of 1/5 scales (height: 1.21 m, width: 1.90 m) were conducted to investigate the deformation behavior in each construction stage. The inner space displacement and the earth pressure acting on the culvert under construction were measured. The results of the experiments were compared with the field measurement date and the design assumption. From the results, it was found that the coefficient of earth pressure increased according to the banking height though the deformation of culvert differed slightly from the design.

Yasuo Sawamura

Bio

Doctor of Engineering, Department of Civil and Earth Resources Engineering, Kyoto University

Authors

Daro Angel Bulla, Leonardo Rosas Sànchez

Abstract

The Sector Cisneros - Loboguerrero (about 13 km in length with 12 short unidirectional tunnels) is a new traffic road still on construction which is located in the existing Highway Buga – Buenaventura (Colombia). Due to the steep topography, the traditional portal approach was not possible to implement at the entrance portal of tunnel 11: an open excavation to provide the necessary cover to begin tunneling would have required slope cuts between 50 - 100 m high.

To study the rock mass behavior, 2D and 3D models were carried out in order to predict the stress-strain response of the slope due to tunneling, to define the stabilization instruments to employ to ensure the excavation stability.

For this specific project with very steep topography, the skew portal approach has reduced both the construction time in one year and the construction cost in 40% and, at the same time, conserving at maximum the natural ground equilibrium.

Daro Angel Bulla, Leonardo Rosas Sànchez

Bio

Dario Hernando Angel, Senior Geologist Geologist from Universidad Industrial de Santander (1994), Bucaramanga, Colombia. Expert in design studies (67 km), and tunnel and underground constructions (3-32 meters of diameter) for road projects (20 km), hydroelectric projects (32 km), and mining projects (12 km), with 20 years of professional experience in South America (Colombia, Ecuador), and Central America (Mexico, Costa Rica, Panama). Professional experience in the development of predictions and possible alternatives for the design and implementation of successful interventions solving special conditions of instability. The main professional interest has been to set the earth science with a practical approach, to make it a useful tool that provides options and solutions in real time, in order to improve the exploration, design and construction strategies for tock engineering projects.

Leonardo Rosas Sànchez, PhD Civil and Geotechnical Engineer, expert in tunneling projects for both weak and hard rock conditions with conventional excavation (NATM) and mechanized excavation (TBM); 20 years of professional experience worldwide: South America (Colombia, Venezuela, Chile), Europe (Austria, Italy), Middle East (Iran), and Asia (India). Education: (1) Ph.D - Dept. of Civil, Environmental, and Architectural Engineering (2008), University of Colorado at Boulder (USA); (2) MS in Civil Engineering (1999), De los Andes University, Bogotà (Colombia); and (3) BS in Civil Engineering, Pontificia Universidad Javeriana (1995), Bogotà (Colombia). Major professional interests: (1) promoting tunneling in transportation engineering; (2) promoting underground structures in urban areas; and (3) promoting sustainability for the development of infrastructure projects.

Authors

Cèline Schiff-Deb, Peter Karlen, Giselle Janssen, Timothy Dobbs, Bryce Sullivan, Ehsan Alavi, Michelle Rucker

Abstract

Soil conditioning is a critical factor in the successful application of EPB machines in tunneling projects. It allows the operator to modify the characteristics of the ground in order to make it suitable for the tunneling process. Selection of the type of conditioner depends on soil type, properties of the tunnel boring machine, and geological conditions, of which the last is the most important. Proper EPB tunneling and soil conditioning in ground above the water table is challenging. This was encountered in the Northgate Link Extension Tunneling Project in Seattle, WA. In order to improve the tunneling operation productivity, a novel algae-based encapsulated oil was used as a conditioner and the operation of the TBM was improved significantly. This paper reviews the traditional soil conditioning measures that were adopted in the project and compares the results with the encapsulated oil additive.

Cèline Schiff-Deb

Bio

Cèline Schiff-Deb has been trained in France as an agronomist and completed a PhD in molecular biology at Stanford University. For the last 15 years, she has been working with strategic consulting firms and biotech companies on the development and marketing of innovative technologies aimed at disrupting various industries, from cosmetics to civil engineering. At Solazyme, as Director of Marketing, she oversees the development, testing and deployment of Encapso, a breakthrough slurry additive to optimize underground drilling operations (e.g. microtunneling, HDD, large diameter tunnels).

Authors

Jean-Pierre Hürzeler, Daniel Stocker, Alberto Del Col

Abstract

During the planning of the 15.4 km-long Ceneri Base Tunnel, extensive investigations were undertaken and an detailed geological prognosis was established. It was apparent that the conditions were heterogeneous, including large stretches with favorable rock conditions interrupted by numerous fault zones with risk of squeezing rock due to the overburden of up to 800 m. The parallelism zone (structures run parallel to the tunnel) was assessed as being particularly problematic.

Extensive studies prior to the tender compared TBM and drill and blast tunneling method. As a result the possibility of TBM-tunneling from Sigirino northwards was ruled out, mainly because of the risk of jamming due to the deformations in the numerous fault zones.

The article first shows a comparison of the geological prognosis with the conditions encountered while excavating the tunnels. Further a back analysis of the geotechnical parameters will investigate the suitability of a TBM.

Jean-Pierre Hürzeler

Bio

Jean Pierre Hürzeler completed his MSc in Geology at the university of Freiburg in 2003. He has been working three years as a site geologist at the Faido site of the Gotthard Base Tunnel before he changed to the Ceneri Base Tunnel site in 2010. He has been following the alpine geology on these sites for many years and in the meantime he is responsible for the whole mapping and the interpretation of the geology in the Ceneri Base Tunnel.

Authors

Bill Zietlow

Abstract

In an oil field that had been depleted with conventional wells but still contained significant reserves, a recently constructed extraction alternative consists of a drilling room below the oil-bearing formation at the bottom of a 1600-ft deep shaft from which upward sloping shallow angle wells are being drilled to allow oil collection by gravity. The drilling room is 96-ft diameter with a flat ceiling supported by rock bolts and shotcrete structurally connected to the shaft liner, which doubles as a large tension support element. The drill room was constructed in competent sandstone with sequential excavation methods and designed with a 3D finite element model. A specific excavation sequence was implemented to maximize stress arching above the roof. Special design consideration was also given to optimizing the drilling room location to take advantage of the geology for construction and support while giving good positioning to the well drilling equipment.

Bill Zietlow

Bio

Mr. Zietlow is a professional engineer with nearly 20 years' experience designing ground support structures. He works on underground, support of excavation, and retaining wall projects across the country out of Denver, Colorado.

Authors

Catherine Larive, Damien Rogat, David Chamoley

Abstract

Creep is a major research issue in fibre reinforced concrete. RILEM has recently devoted a working group to this subject. Many test methods exist to assess creep on structural elements subjected to long-term flexural loading. Most of them are performed on notched beams on isostatic support. Asquapro launched an experimental programme to assess the creep behaviour of fibre reinforced sprayed concrete (FRSC). A test method was especially designed to take into account the specifications of FRSC for underground support (unnotched specimens on hyperstatic support).

The aim of this paper is to present the results of this programme. Up to now, specimens have been submitted to loading for about 200 days. Important risk assessment information is expected in terms of FRSC failure for underground support. Differences between fibres, either of the same type or of different types, (metallic/macrosynthetic), are clearly identified and compared to specimens reinforced with welded mesh.

Catherine Larive

Bio

Doctor Catherine LARIVE initially studied alkali-aggregate reaction (AAR) in concrete for ten years at the Laboratoire Central des Ponts et Chaussèes (now named IFSTTAR), a public civil engineering research centre in France. A specialist in both sprayed and cast concrete and in structure durability, she has a PhD in Materials and Structures Science. She works in the field of tunnel inspection, repair, refurbishment and fire protection.

Since 2012, she has been chairwoman of ASQUAPRO, a French association promoting the quality of sprayed concrete, and has chaired its technical committee for 15 years. Since 2003, she has represented the French Tunnelling Association (AFTES) in the ITA's WG12:"Shotcrete Use". She has been the chairwoman of the « Sprayed Concrete » group of AFTES since 2015. She has also been a member of the RILEM TC CCF "Creep behavior in Cracked Sections of Fiber Reinforced Concrete" since 2014. She is currently Chief Engineer at CETU (Tunnel Engineering Centre), a French public body, where she heads the Materials, Structures and Tunnel Durability Department.

Authors

Dae young Kim

Abstract

Jinhae-Geoje gas pipeline tunnel project is the largest (7.8 km) and the deepest (90 m) subsea tunnel in South Korea. This tunnel will house a pipeline to carry natural gas from mainland to Geoje island south east of the country to alleviate the increased demands for natural gas especially in winter season. Tunneling is currently underway using a slurry shield TBM of 3.5 m diameter. This paper describes the major design elements of the tunneling machine and its performance evaluation. For this purpose, a thorough analysis of geotechnical information was performed to evaluate the tunnel elevation to reduce the risk of tunneling under high water pressure in unstable and permeable rock mass under 9 bar water pressure. TBM specification and TBM performance were also analyzed using different methods including well known models as well as a rotary cutting machine test developed in house in Hyundai Engineering and Construction Company.

Dae young Kim

Bio

Manager in Underground Space Team of Hyundai Engineering and Construction/R&D division in charge of Mechanized Tunneling Projects including field consultation/visit for Hyundai projects (MRT6 C931 Project in Singapore (EPB), Yulchon Project in Korea (EPB)) (e.g. for problems like low performance, tail seal brush leak, foam, downtimes, soil slump test, …), TBM selection and performance evaluation for bidding, and research projects on TBM performance and lace design (KOREA).

Authors

Rodolfo D Aradas, Juan Fernandez, Anthony Harding, Darío Tsingas

Abstract

The adoption of tunnelled combined sewer and outfalls leads to design linings which are often subject to internal pressures that are larger than the external pressures, resulting in significant tension loads. The need to meet stringent durability conditions for the normal design life of 100 years often drives client specifications to require a double pass solution with a cast in situ secondary concrete lining.

However, improvements in concrete technology and the need to seek efficiency in terms of time and costs, have driven designers to consider single pass segmental linings. The Riachuelo Sanitation project in Buenos Aires is subject to these constraints both upstream and downstream of a sewage treatment plant. This paper describes how the challenges of up to 2 bar pressure differential have been by careful analysis of soil structure interaction to ensure that the full benefit of external ground pressure is realised, resulting in a more optimal design for the constructor.

Rodolfo D Aradas

Bio

Dr. Aradas is a Civil Engineer, graduated with a PhD in water resources and geomorphology in the University of Nottingham, UK.

His technical expertise includes a wide range of projects, from developing urban infrastructure master plans and conceptual designs, to detail engineering and construction plans. Rodolfo is currently leading the Tunneling and Earth Science Engineering Group in Latin America, having work in many projects worldwide, from the hydraulic design of pumping stations in Abu Dhabi, to mayor tunnels in Buenos Aires and Panama.

As a scholar, he is a professor of hydraulics at the University Of Buenos Aires, and the author of many international publications.

Authors

Adam L. Bedell, P.G., Rick Ponti, P.G., Yong Wu, PhD, P.E., Steve Fradkin, P.G., Brian Jones, P.E.

Abstract

Estimation during tunnel design of rates and amounts of groundwater infiltration into hard rock tunnels during construction is difficult. There is a few industry accepted means of estimation, and if properly applied, a reasonable estimate of groundwater infiltration rates is obtainable. The City of Atlanta's Department of Watershed Management acquired the Bellwood Quarry in 2006 with an intention to create a water storage facility with a volume of approximately 2.4 billion gallons. Dewatering of the quarry provided the basis for a large scale pumping test. Multiple monitoring points were used to monitor drawdown across approximately 300 acres. The results from the four month long pumping test are then compared to the baselined groundwater infiltration rates as provided in the Contract Documents. A large scale comparison between the industry standard accepted means of groundwater infiltration estimation for tunnels and actual in situ bedrock aquifer characteristics compare favorably.

Adam L. Bedell, P.G.

Bio

Mr. Bedell earned both his B.S. and M.S. in Geology from the University of Georgia. He has been working on various tunnel projects in the Atlanta area for the past 15 years and has supervised the grouting of 28 miles of hard rock tunnel. He has been involved in both design and construction of hard rock tunnels in addition to field direction and program management.

Authors

Han-Kyu Yoo

Abstract

Steel sets such as H-type and lattice girders are most often installed before the hardening of shotcrete to ensure the stability of conventional tunnels in soft ground conditions. While designing the tunnels with the help of numerical analysis, steel sets are not often taken into consideration due to their mostly known function as a temporary support. To assess the structural performance of the composite support consisting of steel sets and shotcrete, large-scale experiments were performed on two types of arch-shaped specimens by applying the combined effects of axial forces and bending moments. Numerical analysis was also performed under the same conditions to propose an efficient analysis method of the composite support. The results show that shotcrete can resist only axial forces but steel sets can withstand both axial and flexural loads. Based on the results, the supporting effects of the composite support were analyzed under various conditions and support patterns.

Han-Kyu Yoo

Bio

Integrated Ph.D. Candidate., Geotechnical Engineering, Hanyang University, Seoul campus, South Korea. B.S., Civil Engineering, Hanyang University, ERICA campus, South Korea, 2011

Authors

Christopher Caruso, P.E., Zachary Spera, P.E., Joel Kantola, P.E., Thomas Hennings, P.E., William Levy, Moussa Wone, P.E.

Abstract

Because of its size, depth, complexity, exposure, and limited access once a Combined Sewer Overflow (CSO) tunnel system goes online, designing to meet a minimum service life has become a standard of practice. This paper provides an overview of the 100-year design life requirement used to design the system of deep tunnels, drop shafts, and diversion structures of the DC Water Clean Rivers Project (DCCR). The DCCR is being implemented to reduce CSOs into the Potomac and Anacostia Rivers, while decreasing flooding in neighborhoods during extreme rain events by capturing, storing, and conveying diverted CSOs to the Blue Plains Advanced Waste Water Treatment Plant. The authors provide an overview of commonly referenced publications; the testing framework used by the program manager to characterize the CSOs; and incorporation of these findings into the specifications and design; which may act as a guideline in implementing durability requirements for other CSO tunnel systems.

Thomas Hennings, P.E.

Bio

Mr. Hennings has nearly 25 years of structural experience with over 17 years specializing in underground projects including cut-and-cover, bored, and mined tunnels, as well as deep excavation support systems. Over six years of that experience was spent as a construction design engineer on several heavy civil construction projects that included a NATM tunnel and several microtunneling drives.

Mr. Hennings was also responsible for underground designs on several rail and highway transit projects. In his current role on the DC Clean Rivers project, Mr. Hennings provides structural review oversight for the Owner on several of the project divisions. Currently, he is working on the Catskill Aqueduct Repair and Rehabilitation (CAT-RR) Project for the NYCDEP as tunnel lead, responsible for the design of a program to improve overall system performance and reliability.

Authors

Roland Plassart, François Laigle, Adrien Saitta, François Martin

Abstract

The storage of nuclear waste raises many new challenges relative to underground space technologies. In the case of Intermediate-level nuclear waste, a large diameter gallery (typically a 12m excavated section) may actually to be the cost effective solution. This paper aims to demonstrate the feasibility of such a gallery in the Cigeo specific context. The paper starts with a review of the data from existing tunnels excavated in similar conditions (500meters overburden with anisotropic initial conditions, soft rock mass surrounding excavation). The paper then details the results of long-term behaviors in the lining, as observed in the Chamoise tunnel since its excavation, more than 20 years ago (measurements made daily). Finally, a back analysis using a 3D numerical model is discussed and compared with the theoretical results derived from the two viscoplastic laws (L&K and H&B Lemaitre laws) which are the current modeling hypothesis used in designing the Cigeo galleries.

Adrien Saitta

Bio

Adrien Saitta has 26 years of professional experience in applied research and geotechnical tunnel design. He has a diploma from the ENTPE and an ENPC doctorate in geotechnics. After having been head of the geology, geotechnical and designing pole at the CETU, he was named deputy-director of the Aix-en-Provence Ponts et Chaussées laboratory (130 staff members). He is currently a geotechnical expert for Egis Tunnels. He participates in various expert committees (Seine Nord project, Grenoble Northern by-pass, the A89 tunnels, EOLE, Grans Paris), as project management assistant (TGV Méditerranée tunnels) and project management.  

Authors

Mahmood Khwaja, Daryl Poduska, Prakash Donde, Todd Wanless

Abstract

The proposed Minne Lusa Stormwater Conveyance Sewer is part of the Phase 3 Major Combined Sewer Overflow projects to be scheduled as part of the City of Omaha’s Long Term Control Plan (LTCP). The system features a 6,110 foot long, 14-foot inside diameter tunnel to provide for conveyance of separated stormwater from previously completed and future LTCP sewer separation projects to the expanded Storz West and Pershing Detention Basins and subsequently, the Missouri River. The tunnel will operate as a pressurized system and convey flows of up to 2,500 cfs resulting from a 10-year, 24 hour storm event. This paper provides a synopsis of the project with a focus on the overall design aspects related to the tunnel, the drop shaft where upstream collector flows will be captured via a tangential inlet structure and discharged into a de-aeration chamber, temporary and permanent works at the portal and the de-aeration chamber. Tunnel alignment and profile and geological profile are presented, as well as an overview of the construction related impacts considered during design.

Mahmood Khwaja

Bio

Mahmood Khwaja is an accomplished geo-structural engineer with 25 years of experience in design of above and below-ground structures, and as a Project Manager and Technical Lead. He is currently a Chief Project Manager with COWI North America. His experience includes working on cut-and-cover, mined, bored and jacked tunnels; analyzing complex soil-structure interaction behavior using numerical methods; analysis and design of above and below ground transit stations, tunnels, deep shafts, de-aeration chambers, large scale water structures, excavation support systems, and soil improvement. His project experience includes: Boston Central Artery/Tunnel, 2nd Avenue Subway, Silver Line Phase III, Baltimore Red Line LTR, Anacostia River Tunnel, Minne Lusa Stormwater Conveyance Sewer, and the Doha Metro. Mahmood is experienced in alternate delivery methods, including design-build and PPP. Mahmood is a Professional Engineer in several states; has international geographic experience including the US, UK, Middle East, and Pakistan.

Authors

Victor Dobrev Tashev

Abstract

An intensive development of Sofia Metro System is in progress now. The first two metro-diameters are almost completed and the third one is under design. Construction works involve the use of all the available tunnelling technologies including conventional methods, cut and cover and mechanized techniques.

Considered bifurcation section represents a part of the first metro diameter. It is located between Station 13, Station 14 and Station 18 (Fig. 1). Applied technical solution and construction methods are discussed in this paper. Additionally, some details concerning design approach, method of analysis and monitoring aspects are described.

Victor Dobrev Tashev

Bio

Assoc. Professor in the field of tunnel construction with more than 25 years experience

Department of Hydraulic Engineering, UACEG – Sofia, Bulgaria

Member of Bulgarian Association for Geotechnical and Tunnel Construction (BAGTC)

Authors

Jeremiah Jezerski

Abstract

Liberty University plans to grow the on-campus student population to 16,000. However, an at-grade crossing of two active rail lines posed un-safe and inefficient ingress and egress at one end of the campus. Liberty's solution was to build tunnels to convey four travel lanes beneath the active rail lines. Conventional pushing or jacking the tunnels into place created the possibility of "blowing-out" the opposite side of the rail embankment. Brierley Associates devised an innovative method by designing a reaction wall on the opposite side of the tunnel launch pad and pull the boxes into place, which according to literature searches had not been done in North America. Our design significantly reduced costs associated with conventional jacking and alleviated "blow-out" concerns. This new access point mitigates safety and traffic congestion issues on campus and connective public roadways. This paper will provide insight to feasibility analysis, design, contractor procurement and project challenges.

Jeremiah Jezerski

Bio

Mr. Jezerski, served as Project Manager for design and construction of the Liberty University Twin Box Tunnels. Jeremiah earned his undergraduate degree in civil engineering at Syracuse University and a Master's degree in Geotechnical Engineering from Cornell University. His postgraduate research at Cornell focused on pipeline response during large-scale soil interaction experiments, specifically material characterization, instrumentation, and finite element modeling. As Senior Project Engineer at Brierley Associates, Jeremiah provides assistance for design and construction management services on a wide spectrum of projects. Recent examples include temporary support for tunnel and shaft excavation for the Kaneohe/Kailua Sewer Tunnel Project, Oahu, Hawai'i and Bi-County Water Tunnel Project in Maryland. Jeremiah also led the design for a temporary/permanent secant pile wall for the construction of a 100ft. x 200ft. ft. x 40ft deep backwash tank as part of the improvement program at the Binghamton-Johnson City Waste Water Treatment Plant in Upstate New York.

Authors

Indra Banerjee

Abstract

Shielded TBMs with precast segmental lining ground support allow successful completion of tunnel drives through almost any type of ground. However, on many projects quality issues with the lining are frequently associated with time-consuming and cost-intensive repairs. Identification and control of influencing factors during lining installation minimizes follow on repair work.

This paper presents a comprehensive review of conceivable quality issues with segmental lining. Potential root causes, contributing factors and proactive preventative measures are outlined. The paper also summarizes the standard quality control and quality assurance approaches and evaluates possible alternatives.

Indra Banerjee

Bio

Indradeep Banerjee is a Project Engineer for CH2M HILL. Mr. Banerjee is an MSc in Geotechnical Engineering from Singapore and a BE in Civil Engineering from India. For the past 23 years, Mr. Banerjee has worked on a wide range of underground construction projects in India, Singapore and the US for contractor, owner and consultant. He is with CH2M HILL for the last 14 years, focusing on construction management of micro tunnels and tunnels.

Authors

Carlos A Jaramillo, Seng Hing Ngu

Abstract

The Murum Hydroelectric Project is a 944-MW development consisting of a 145 meter high RCC dam, two 9 meter excavated diameter pressure tunnels 2660 meter long, pressure shafts and surge shafts, and a surface powerhouse. The project is located in the eastern section of the State of Sarawak, Malaysia, about 200 kilometer from Bintulu, in the Rajang Fold-Thrust Belt, an Upper Cretaceous to Upper Eocene fold and thrust belt that extends under most of Sarawak. The Belaga Formation consists of a thick sequence of deep marine sediments currently appearing as steeply dipping strata of thin to thick bedded, fine to medium grained sandstone interbedded with argillaceous rocks, resulting on a "Flysch" type geologic environment.

The project pressure tunnels were excavated perpendicularly to these strata resulting on frequent change on rock conditions and behavior, and required rock support.

This paper describes the characterization of the rock mass, design of rock support, and incidents during construction. Particularly interesting were convergence issues in Tunnel 1 resulting from Tunnel 2 excavation.

Carlos A Jaramillo

Bio

Carlos Jaramillo, an international consultant in tunneling for hydropower projects, has over 35 years of experience and has been involved in all phases of the design of major tunnels, dams, hydropower, and other infrastructure projects, starting from initial site reconnaissance, conceptual engineering, and feasibility studies, continuing on to the design and construction stages, and completing the project life cycle with the evaluation of dam and tunnel safety and the rehabilitation of existing dams and tunnels. His experience ranges from the design of tunnels, caverns, and other underground structures to the geotechnical design and layout of dams and related works.

Authors

Mehdi Bakhshi, Verya Nasri

Abstract

Fiber reinforcement has emerged as an alternative to steel bars in precast concrete segments due to advantages such as saving cost and reducing production time while developing a more robust product with improved handling and long-term durability. ACI recently drafted a new report as the first design guideline on FRC tunnel segments to provide specific guidance for this emerging technology. This document offers general information on the history of FRC precast segments from tunneling projects throughout the world; a procedure for structural analysis and design based on governing load cases, and a description of the material parameters, tests and analyses required to complete the design. This paper summarizes the design considerations in this ACI guideline prepared by the authors of this paper as the main contributors. Application of this guideline to design of a mid-size tunnel results in elimination of steel bars and reduction of crack width under service loads.

Mehdi Bakhshi

Bio

Currently Senior Tunnel Engineer, AECOM
PhD in Civil Engineering from Arizona State University, Tempe, AZ
More than 20 journal and conference papers

Representative projects:
South Hartford Conveyance and Storage Tunnel, CT
Baltimore Red Line Cooks Lane Tunnel, MD
Westside Subway Extension, Los Angeles, CA
Regional Connector Transit Corridor, Los Angeles, CA
Indianapolis Deep Rock Tunnel Connector Pump Station, IN

Authors

Wern-ping N Chen

Abstract

A cost effective approach for the fire design of the concrete final lining of the Ohio River Bridges East End Crossing Tunnel has been implemented. As a result from a proposed fire suppression system, the project design Heat Release Rate (HRR) (from the RWS fire curve) was able to be reduced from 300 MW to about 50 MW. With this reduced HRR, concrete lining without passive fire protection may be acceptable for safety reason, if the concrete lining will not result in explosive spalling during the fire event. Concrete explosive spalling test was proposed to verify this assumption. Since no standard concrete fire explosive spalling testing procedure exists, a project specific testing procedure was developed and fire tests conducted. From the test results, it is concluded that the proposed tunnel concrete lining with the fire suppression system alone won't result in explosive spalling when experiencing the project 300MW HRR fire.

Wern-ping N Chen

Bio

Nick Chen is Regional Vice President and Chief Engineer - Tunnel of Jacobs Engineering North American Infrastructure group. With 28-year experience, Nick specializes in design and construction of underground structures, including water and wastewater tunnels, transportation tunnels, and underground facilities for the US Department of Energy. Total construction cost of his underground projects exceeds US $30 billion.

He is the Tunnel Engineer of Record for the recent US underground PPP projects, including Port of Miami Tunnel and Ohio River Bridge East End Crossing Tunnel.

Authors

Tiago G S Dias, Adam Bezuijen

Abstract

The construction of mechanized tunnels in soft ground has evolved significantly over the last 20 years, especially in the control of the face pressure and the closure of the soil-lining void to reduce the induced settlements. On the other hand, several mechanisms of the TBM excavation cycle are still not taken into account for routine design calculations, such as the increment of water pressures in front of the tunnel face, the flow of excavation fluids around the shield, the dynamic equilibrium between the grout pressures and the excavation convergence, among others. This paper discusses how these factors, which are routinely considered exceptional, can be easily verified and incorporated in the state-of-practice of design. The study defines a framework where the TBM operational parameters can be assessed together with the induced soil displacements and lining forces for different project conditions. The compliance of the model with field measurements is presented.

Tiago G S Dias

Bio

Tiago G. S. Dias is a PhD Student in Ghent University, Belgium. He graduated in Civil Engineering from the University of Brasilia in 2011, where he also obtained his MSc degree in Geotechnical Engineering a year later. He received the first Fernando Emmanuel Barata award from the Brazilian Society for Soil Mechanics and Geotechnical Engineering (ABMS) for the best national graduation project in the biennial 2010-2011. He worked in the design of embankment dams and tunnels and his research has gone through new applications of geosynthetics in embankment dams, deep foundations, alternative methods for the construction of subway stations and TBM tunnel analysis. His PhD is focused on the analysis of the interaction between tunnels and pile-supported structures.

Authors

João Carlos de Lima Pereira

Abstract

During the conceptual design of immersed tunnels the shear keys play a major role in its developments, as well as in the construction phase. Shear key are devices employed to transfer among the segments of a tunnel element the horizontal as well vertical loads coming mainly from soil settlements and/or earthquake events.

At the shear key location there will be large concentration of forces, and because of that the reinforcement is too heavy and difficult to be prepared, which causes extra burdens during the construction.

This paper is related with the possibility to eliminate the horizontal shear keys by replacing them with tubes used to protect and carry the pre-stressed cables located at the top and at the bottom slabs. By releasing the vertical constraints of the tubes, and forcing them to transfer the loads only in the horizontal direction, one can have the tubes working as horizontal shear keys.

João Carlos de Lima Pereira

Bio

Civil Engineer, Universidade Paulista, São Paulo/Brazil, 1989

Currently at DERSA, a company for transport and road planning of the State of São Paulo/Brazil

Authors

Stefan Ritter

Abstract

For many urban tunnelling projects it is essential to successfully predict and prevent building damage. Although various case studies and experiments have shown that buildings considerably modify greenfield soil movements, widely accepted damage assessment methods neglect this soil-structure interaction and simplify structures as linear elastic beams. This paper summarises an experimental investigation of the response of more realistic structures to tunnelling-induced deformations. Small scale structural models with façade openings and brittle material properties were 3D printed and tested in a geotechnical centrifuge. Soil and structure displacement data were obtained by imagebased measurement. Comparison of multiple centrifuge tests provides insight regarding the intricacies of this soil structure interaction problem, and further highlights that structural damage in the form of cracking significantly depends on the position of the structure in the settlement profile. The results provide a basis from which to predict building settlement response with greater certainty.

Stefan Ritter

Bio

Stefan Ritter joined the Geotechnical Engineering and Environmental Research Group at Cambridge University (UK) in October 2013 in order to undertake PhD research into the response of surface structures to tunnelling-induced settlements. He is supervised by Dr Matthew DeJong and his research is funded by Crossrail. At Cambridge University, Stefan supervises students in Geotechnical Engineering and demonstrates the Dimensional Analysis laboratory.

In 2011, Stefan graduated from the University of Leoben (Austria) in Mining and Tunnelling. He subsequently went on to get industrial experience working primarily as a tunnelling engineer on an Austrian expressway tunnel project. During his studies in Austria he gained tunnelling experience working as an intern for tunnel construction and design companies. Stefan was a visiting research student at the MIT (USA) where he worked on his Master’s thesis which was awarded by the Austrian Society for Geomechanics.

Authors

Günther Meschke

Abstract

In 2010, the Collaborative Research Center "Interaction Models for Mechanized Tunneling" was installed at the Ruhr-University in Bochum, Germany. Organized into 4 project areas, research performed by an interdisciplinary team of app. 35 researchers is concerned with i) with the characterization of the in-situ and the disturbed ground conditions in the vicinity of the cutting wheel and advance exploration methods, ii) novel segmental lining designs with enhanced robustness and the interaction between the grout and the surrounding soil, iii) the computational simulation of soil cutting, advancement and logistics processes, the material transport in the TBM and real time prognosis models to support the TBM steering, and iv) risk analysis in urban tunneling. These research themes are each supported by computational models and are all included in an SFB overreaching tunnel information model. In the presentation selected major results from the SFB 837 obtained so far are presented.

Günther Meschke

Bio

Prof. Dr. Günther Meschke is the Head of the Institute for Structural Mechanics at the Ruhr University Bochum and Coordinator of the SFB 837 and the Research Department "Subsurface Modeling & Engineering". His research in the field of computational structural mechanics is focused on multifield and multiscale models for porous materials, numerical simulation models for underground engineering and lifetime analysis of structures. After graduating in Civil Engineering he received his doctorate in 1989 from the Technical University of Vienna (TUV). After a post-doctoral period at TUV and Stanford University (USA) he was appointed Associate Professor at TUV in 1996 and Full Professor at Ruhr University Bochum in 1998. Prof. Meschke is an Ordinary Member of the German Academy of Science and Engineering, the North RhineWestphalian Academy of Sciences, Humanities and Arts and an Associate member of the Austrian Academy of Sciences. He is the author of app. 270 scientific publications.

Authors

Johannes Jaeger

Abstract

A composite shell lining typically consists of an outer permanent sprayed concrete shell, a water proofing layer and an inner sprayed or cast concrete shell. Composite shell linings become more and more popular and have been built recently on large scale infrastructure projects, especially in the UK. Surprisingly there is very little published literature on the actual structural design of composite linings. Composite action of the outer shell initially carrying short term ground loads and the "unloaded" inner shell require nonlinear concrete modelling to be able to assess the bearing capacity of the composite lining structure adequately. The composite action interfaces between the waterproofing membrane and the inner and outer shells can be considered either by simplified closed form solutions as well as numerical models. Strength and stiffness parameters related to those models govern interaction of inner and outer shell. As those parameters find their way into the material specifications their significance regarding to the overall structural behaviour has to be critically analysed.

Johannes Jaeger

Bio

Before Johannes JÄGER joined Beton- und Monierbau GmbH (now: BeMo Tunnelling GmbH) in 1996 he was a teaching and research assistant at the Institute for Strength of Materials/University of Innsbruck. Within BeMo he worked as a structural designer, tunnel design engineer and SCL/SEM engineer for various projects in Germany, UK, USA and Austria.

Since 2007, he is head of Bemo's design division.

Authors

Goetz Vollmann, Alena Conrads, Markus Thewes

Abstract

Large fires and explosions have to be considered as severe threats to underground infrastructure. Complex numerical assessments are needed to determine its performance under the corresponding loads and influences.

For the identification of objects within the network that provide the biggest criticality in terms of resulting influence on the network's functionality comprehensive approaches are needed. These are often too complex and time consuming for an a priori and in depth assessment of each tunnel or underground hub within the specific network sector.

Within a national research project the authors developed an approach for a quantitative structural risk analysis that combines a complex numerical (2D and 3D) with a fuzzy-logical procedure. This enables a quicker determination of possible risks within a predefined scope. The paper describes the methodology and shows selected results from the analyses, which were conducted for the German road network.

Goetz Vollmann

Bio

Dr. Vollmann is head of research and assistant Professor at the Institute for Tunnelling and Construction Management (TLB) at the Ruhr-University in Bochum. He has been working on the topic of safety and security of underground infrastructure for more than 10 years, especially on the risk assessment for underground infrastructure, structural assessment under fire and explosive loads and the identification of critical infrastructural elements. He has developed measures for the safe operation of tunnels and offers various publications and presentations on the topic. Dr. Vollmann an active and vital member of the international community and several committees, such as the steering board of ITA-COSUF, the committee on operational safety of underground facilities of the International Tunnelling Association.

Authors

Hamid Javady, Ashley Galagusz, Shaun Pinard, Izabela Bugan

Abstract

The Bremner Boulevard Cable Tunnel located in Toronto, Ontario, Canada is a 600-meter long rock tunnel with an inside diameter of 4 meters which was mined by a rock Tunnel Boring Machine (TBM). The launch shaft, located at Bremner Boulevard and Rees Street, is approximately 30 meters deep and was constructed through overburden and shale bedrock. The entire tunnel alignment was constructed through shale bedrock in a heavy urban area. The support system consists of c-channels, rock bolts and wire mesh. One of the challenges in constructing the tunnel was making a 90 degree turn after mining for 350 meters. Another major challenge occurred when the tunnel encountered poor rock sections and a rock wedge fell from the tunnel crown and damaged some of the TBM equipment. The support system was re-evaluated in order to determine the best course of action. Inspections of the rock were performed and a joint study was conducted to quantify and qualify the rock wedges along the tunnel alignment. Over 80 joint measurements were taken and the data was entered into the Unwedge software. The software revealed the sections of the tunnel alignment that were subject to the highest incidence of falling and sliding wedges. The Rock Mass Rating (RMR) system was also used to qualify the rock. The RMR system proposes guidelines to follow for support systems based on the rating given to the rock. The results from the RMR analysis and the joint study were compared, and a decision was made to increase the support system two-fold at certain sections of the tunnel for a total of 175 meters. These were the sections that had the worst quality rock and the highest probability of wedge failure. The final major challenge was to back out the TBM once mining was complete, since it was not possible to construct an exit shaft for the machine.

Hamid Javady

Bio

Hamid Javady is a senior tunnel engineer with 25 years of experience in large-scale projects for transit, water, and wastewater tunnel projects. He has experience regarding contractor procurement, segment and TBM procurement and evaluation. Hamid has experience working in challenging underground project environments ranging from small to large diameter tunnels, drilling and blasting, and working with EPB, slurry, and dual-mode TBM tunnelling. His work experience includes tunnel design in rock and soft ground, shaft design, Feasibility Studies, cast-in-place lining and precast segmental lining design, assessment of different types of tunnelling methodologies and construction, geotechnical investigations, GBR preparation, cost estimation, jet grouting, compensation grouting, groundwater modeling assessment of in-situ stress, rock mechanics, and productivity analysis. Hamid has a wide range of construction and operational experience in different types of subsurface tunnelling conditions, groundwater hydrology, in situ ground stresses, and lining requirements for long-term serviceability and maintainability. Hamid’s extensive experience includes tunnelling through the hardest rock to the softest ground in challenging situations such as tunnelling beneath cities, rivers, lakes, and mountains. Hamid has experience with deep tunnels and shafts in soil and rock across Canada and the USA with a focus on the GTA.

Authors

Roberto Schuerch, R. Poggiati, G. Anagnostou

Abstract

The paper presents dimensionless design diagrams for the estimation of the stand-up time of the tunnel face in saturated ground of medium-low permeability. The diagrams cover a wide range of soft ground parameters and apply to shallow tunnels (overburden less than four diameters). As the time-dependency of the face stability in water-bearing ground is associated with the consolidation process in the soil ahead of the tunnel face, the stand-up time is determined by means of hydraulic-mechanical coupled, spatial stress analyses. The presented results are important for the tunnel engineering practice, e.g. for estimating the feasibility of atmospheric interventions in the working chamber of closed shields.

Roberto Schuerch

Bio

Roberto Schuerch obtained the Master degree of Science in geotechnical and structural engineering at the ETH of Zurich in 2009. Since 2009 he works in the group of underground construction leaded by Prof Anagnostou at the ETH of Zurich. The main activities over the last six years are consultancy tasks on tunnel projects in difficult ground conditions (e.g. Lake Mead Intake No. 3, Subway Athens, Zurich City Link, Gotthard Base Tunnel, among others), research (PhD candidate) and teaching.

Authors

Toru Sasaki, Shingo Morimoto and Masato Shinji

Abstract

The tunnel face stability is the most important topics in NATM. If the material properties of ground become clear from the field survey, tunnel face behavior can be predicted using numerical simulation before tunnel construction. But the estimation of the safety of tunnel face is difficult when the ground is weaker.

Numerical analysis of tunnel excavation on very weak ground conditions were carried out in this study. And the relationship between the average strain of the tunnel face and the overburden was obtained. It estimates the strain of the tunnel face comparing the critical shear strain obtained by the ground properties. And the allowable overburden was calculated satisfying the critical shear strain of the ground.

Finally, the design chart of the allowable overburden of various cohesion and friction angle of the ground is proposed. It is useful to judge the necessity of additional counter measure against the normal tunnel support.

Toru Sasaki

Bio

I'm a master student of Yamaguchi University in Japan.

Authors

Axel G Nitschke, Vojtech Gall, Ralf Winterberg

Abstract

Macro synthetic fiber reinforced concrete or shotcrete is seen by many design engineers as offering a viable alternative to steel reinforcement in tunnel linings. The technology is now commonplace for primary and permanent ground support in both mining and civil tunnel applications. It has for instance become the standard form of reinforcement in the Australian mining industry, and has been used for a majority of permanent tunnel linings in recent tunnel construction in Norway. Similarly, macro synthetic fibres are becoming a standard solution for the initial lining in the USA.

The use of macro synthetic fiber offers innovative solutions, yielding robust and sustainable tunnel lining designs. Citing recent research and actual projects, this paper presents state-of-the-art design considerations for fiber reinforced tunnel linings relating to structural and long-term performance. Topics include seismic resistance, crack width control, corrosion and durability as well as sustainment of performance with age.

Axel G Nitschke

Bio

Axel Nitschke received his Ph.D. in civil engineering in 1998 and has gained twenty years of in-depth on-the-job experience in all aspects of tunneling, including feasibility and constructability studies, tunnel design, as well as tunnel construction management. He has headed the engineering and construction of a large number of tunnel projects in Europe as well as the United States and specializes in the application of the New Austrian Tunneling Method (NATM), often referred to as the Sequential Excavation Method (SEM). He is well experienced in all ground conditions ranging from soft ground to hard rock and the associated implications for design and construction methods. Dr. Nitschke has held key positions such as Senior NATM Manager, Contract / Claims Manager, Risk Manager, and Project Manager.

Authors

David Americo Fortuna Oliveira

Abstract

One of the key drivers for the selection of mechanised tunnelling methods in good quality rock masses is the aim of good excavation advance rates. Besides the aspects related to ground support and the performance of the cutter head, a good geotechnical performance of the grippers in main beam open tunnel boring machines (TBM) is also required to achieve good excavation advance rates. One well known potential issue of TBM grippers is associated with the bearing capacity of the tunnel side walls while crossing poor rock mass zones. Such a mechanism is similar to that of footings on rock and perhaps the most common problem associated with gripper performance. Depending on the quality of the rock, the rock under the gripper contact may experience significant damage and crushing, eventually affecting the TBM advance rate due to a lack of tunnel wall reaction/support. Such a mechanism is primarily dependent on the rock quality, applied loads and gripper size. In the case of large diameter (D > 12 m) twin tunnels, a second potential issue may arise which associated with the loss of confinement within the rock pillar, even in good quality rock and particularly in bedded sedimentary strata. Punching of the rock pillar may develop due to excessive shear along bedding partings and sub-vertical joints. This mechanism is dependent on both the rock pillar width between twin tunnels and stress conditions around the tunnels, in addition to the previous factors described for the first failure mechanism. This paper presents a methodology for the assessment of the potential failure mechanism associated with TBM gripper in bedded sedimentary rock. The assessment is carried out using both simplified methods considering closed-form solutions and empirical methods, and detailed Abaqus 3D model using rigid elements with a contact algorithm to represent the TBM gripper and explicit discontinuities within the rock pillar for different ground conditions.

David Americo Fortuna Oliveira

Bio

David is a Principal and Chartered Geotechnical Engineer with over 16 years of experience and highly regarded technical competence. David holds a PhD in Rock Mechanics from the University of Wollongong and is currently a Technical Expert and Advisor within the Underground Space, Ground Behaviour and Numerical Modelling groups of excellence within Coffey.

Authors

Jiang Su

Abstract

Spray applied waterproofing membrane has recently been used in many high profile SCL tunnel projects. Its use with permanent primary and secondary lining introduces complex primary-secondary lining interaction, which is an issue that has previously not been fully investigated and understood.,br/>
This paper aims to address this issue by presenting a series of numerical analyses on a typical shallow SCL tunnel in soft ground adopting validated modelling approach and interface design parameters. Three different assumptions on the interface are made: (1) compression only, (b) compression and tension and (c) compression, tension and shear.

The results show that the assumptions of spray applied waterproofing membrane behaviour have a significant impact on the primary-secondary lining interactions. It would be not conservative to ignore the interface tensile and shear bonds during the design. This paper explains the rationale behind these conclusions and discusses the design implications.

Jiang Su

Bio

Jiang Su is a Chartered Civil Engineer currently working for Mott MacDonald in the UK. For the past eight years, Jiang has been involved in the SCL design, research and construction supervision of the Europe's biggest infrastructure project Crossrail. Jiang has a Master degree from Cambridge and a PhD on the Composite SCL tunnels.

Authors

Albert de la Fuente, Isaac Galobardes, Antonio Figueiredo, Marco Aurelio Peixoto

Abstract

The construction of underground lines has a big importance in overpopulated cities such as São Paulo. In that sense, the tunnel boring machine (TBM) method for tunnel construction is a method that allows a high speed of construction. The TBM uses different segments, typically produced with conventional reinforced concrete, which composes the tunnel linings. Regarding new technological advances, steel fibres are added to the concrete mixes in order to create a ductile material. This entails a reduction of the segment damages, the time consumed in the segment production and the construction cost. The aim of this work is proposing a methodology based on the fib Model Code 2010, which allows the design of hybrid segments (structural fibres and traditional reinforcement). This methodology may be used for those situation in which both the transient and permanent load conditions do not entail cracking in the structure.

Albert de la Fuente

Bio

PhD in Civil Engineer and Senior Lecturer Professor in Univeristat Politècnica de Catalunya (Spain). His research field is focused on the design and optimization of fibre reinforced concrete structures and the multi - criteria decision making tools oriented to civil engineer projects. He has published more than 25 papers in JCR indexed Journals and supervised 3 PhD thesis in the last 5 years. He is actively collaborating with national and international companies. Member of various committees; in particular, he is member of the fib TG 1.4.1Tunnels in fibre reinforced concrete.

Authors

Jiang Su

Abstract

Composite sprayed concrete linings (SCL), consisting of two layers of permanent shotcrete separated by a layer of spray-applied waterproofing membrane, represents the latest development in SCL tunnelling, but presents several challenges to designers.

This paper aims to address the following issues: (1) how to simulate composite action, (2) behaviour of a Composite SCL tunnel, and (3) how to utilise composite action to achieve lining thickness efficiency. It firstly sets out the background to the composite SCL concept, and then presents a strategy for numerical investigation. The main part of the paper is the presentation and discussion of the simulation results, focusing on the lining deformation, load sharing and the safety margin of both linings. Interface stresses are also examined. It is found that significant secondary lining thickness reduction may be achieved by utilising composite action. Challenges for the design of Composite SCL tunnels are briefly discussed at the end.

Jiang Su

Bio

Jiang Su is a Chartered Civil Engineer currently working for Mott MacDonald in the UK. For the past eight years, Jiang has been involved in the SCL design, research and construction supervision of the Europe's biggest infrastructure project Crossrail. Jiang has a Master degree from Cambridge and a PhD on the Composite SCL tunnels.

Authors

Anthony M Harding

Abstract

Creating stable, safe, constructible and cost effective support to openings in segmental linings is often an important component of successful delivery of a tunnel project. The many constraints on successful implementation include operational, spatial, geotechnical, structural, and constructability. Failure to address these adequately can lead to significant impacts on cost, schedule, and safety. With reference to past project experiences, this paper provides a guide to the most commonly deployed solutions and their pros and cons to help designers quickly identify the most appropriate solutions for a particular project, or act as a starting point for developing new and/or project specific solutions.

It highlights the challenges that designers and contractors must address together for successful support of tunnel openings, and the constraints that arise. It then describes the common structural forms of support, and how each form can mitigate the constraints, allowing an effective opening support system to be implemented.

Anthony M Harding

Bio

Anthony Harding is the CH2M lead technologist for tunnels. He gained a degree and PhD from Edinburgh University, and joined Halcrow (now part of CH2M) in London in 2000. He has worked on a wide range of tunnel projects, across the road, rail, power and water industries. His experience covers TBM and conventional tunnelling, including the design of new tunnels and assessment of existing tunnels and other assets impacted by tunnelling.

In more recent years Anthony has acted in roles as technical manager, design coordinator, and project manager for multidisciplinary designs, usually within design-build environments. He has a particular interest in TBM tunnelling and gets involved in projects with particularly complex technical challenges. He is based in Brisbane, where he continues to work on a range of local and international tunnelling projects.

Authors

Jalaleddin Y Rafi, Fredrik Johansson, Håkan Stille

Abstract

In tunneling projects, specifically in sedimentary and hard rock geology, cement grouting is performed to decrease the flow of water into the tunnel. Currently there are debates about taking advantage of high pumping pressure to jack fractures and filling them in shortest time even if it may prevent to achieve required sealing efficiency. In this study a theoretical approach, which enables estimation of penetration length of grout as well as deformation of the fractures, is used to quantify the consequences of elastic jacking in a Norwegian tunneling project, where high-pressure grouting is practiced, in compare with grouting in an urban train tunnel in Sweden, at which much lower pressures have been applied. It is shown that although no movement on the surface was noticed due to elastic jacking, the negative consequences of the induced deformations might damage the sealing efficiency of the grouting and spoil merits of using high pressures.

Jalaleddin Y Rafi

Bio

Ph.D. in rock mechanics with focus on grouting in tunneling and hydropower projects More than 8 years of consultancy and management experience in urban tunneling and hydro-power projects

Researcher at division of soil and rock mechanics at Royal Institute of Technology Consultant, design of tunnels and dam construction at Sweco, Stockholm

Authors

Sotiris Psomas, Colin Eddie

Abstract

Steel fibre reinforced concrete (SFRC) Segmental Tunnel Linings have successfully been used for over 20 years in the UK and has been adopted in a number of high profile projects such as High Speed 1, Crossrail, Thames Tideway, as well as High Speed 2. Tunnel lining and especially SFRC design are not covered in Eurocodes. This shortage of SFRC tunnel design rules seems to be partially addressed by several international publications. However, in the UK, the 'design-assisted by testing' (DAT) approach has also been adopted. The Paper discuss UK's best design practice and focuses on the DAT methodology as applied in the case of the 6.9km (4.3miles), 7.8m (25.6 feet) ID Lining for the ₤650million Lee Tunnel Project. The SFRC design approach, the full scale testing at the British Research Establishment (BRE), the in-situ validation testing and the construction innovations are presented. This experience will be transferred to the ₤4billion Thames Tideway Tunnel.

Sotiris Psomas

Bio

I graduated from National Technical University of Athens and hold Masters from University of Newcastle (Rock Mechanics) and Oxford University (Engineering Science). I have 20 years of experience in design, consulting, research and development. I am Senior Engineering Manager with UNPS Limited (part of Morgan Sindall Group). I held key roles have ranged from leading structural tunnel lining and geotechnical design to research and development, site supervision and design management. I have successfully performed the roles of Design Team Leader on major infrastructure projects. I was the principal designer of SFRC Linings of Lee Tunnel Project and have been involved in the detailed design of the SCL Station Works for Crossrail C510. I am currently one of the main authors of the ITAtech document on design guideline for FRC segments and member of the BSi PAS8810 Code of Practice for the design of Concrete Tunnel Linings in Soft Ground.

Authors

Alejandro N Jimnez

Abstract

Urban tunnelling by conventional means is nowadays a common practice since traffic solutions are a priority for the proper operation of large cities. In many cases, surface structures must be protected from damage, while poor ground conditions are encountered. Forepoling systems play an important role in these situations and often contribute to great success in construction. However, a clear understanding of the phenomena involved in their structural behaviour and their interaction with the ground during excavation processes is still lacking; due to the complex nature of the problem, it becomes difficult to derive simple analytical design methods, which at the same time take into account most of the factors needed to a successful implementation. In this paper a forepoling system design approach is presented, which departs from a simple analytical method for defining potential face collapse mechanisms. Results are verified via 3D numerical models and design charts are included.

Alejandro N Jimnez

Bio

Fermín Sánchez, civil engineer, graduated 1994 at the National University of Mexico, made his Master Studies at the Technical University of Catalonia in Spain where also made part of his PHD studies and collaborated as a researcher during 10 years. He will graduate as PHD in 2016 with the publication of a book on tunnel design. He has participated in the design and construction of over 60 tunnels in Mexico and Spain and worked as consultant for the Federal Road Administration and the Federal Electricity Commission in Mexico.

He has published over 15 national and international papers on constitutive modeling and tunnel design and participated as lecturer and professor of rock mechanics and tunneling in courses in Spain, Argentina, Colombia and Mexico. He is technical manager of the firm Consultec in his country and professor on applied mathematics, numerical methods in geomechanics and tunnel design at the National University of Mexico.

Authors

Ömer Aydan, R. Ulusay, N. Tokashiki, M. Imazu

Abstract

A new rock classification named as Rock Mass Quality Rating (RMQR) proposed by the authors. This new rock classification quantify the state of rock mass and possible geo-mechanical properties of rock masses can be estimated using the classification system together with intrinsic geo-mechanical properties of intact rock. As the instability modes of underground openings can be structurally controlled due to orientation of discontinuities in rock mass and in-situ stress induced. In this paper, the authors would establish some criteria for the design of support system with the consideration of anticipated loading conditions (structurally controlled or stress induced) and type of underground structure according to the new rock classification system called Rock Mass Quality Rating (RMQR) and propose some guidelines for selecting the proper size of rockbolts, rock anchors, shotcrete, steel ribs and concrete liner. The proposal is based on both past experiences in various underground structures, theoretical background and reasoning and anticipated behaviour of rock mass under given in-situ stress conditions and excavation technique (i.e drill & blasting, TBM, Roadheader etc.). The authors also utilize some databases developed for large underground caverns and tunnels excavating in squeezing or rockbursting ground conditions.

Omer Aydan

Bio

Chief Mining Engineer, Arkagünevi Mine ETIBANK Bigadiç Mining Complex, Turkey

Authors

Elisa Comis, M. Younis, R.Goodfellow

Abstract

The success of a tunnel project relies on many factors, but one of the most important is also the most overlooked: Coordination by all companies involved during the design stages. This is particularly true of segment design and TBM design. Tunnel lining with segmental rings is usually designed according to the standards of reinforced concrete construction based on a given GBR. But for TBM tunneling, the determination of loads during ring erection, advance of the TBM, earth pressure and bedding of the articulated ring are all part of the design of the lining as well. TBM design can be heavily affected by the segment arrangement, dimension and weight, but these are usually given as a fixed input to the TBM manufacturer—a process that can cause unnecessary complications.

The authors propose that the industry evaluate the process as it stands. In order to find the optimum between lining design and TBM cost and operational workflow, both designs should be finalized concurrently. This requires coordination between the TBM Manufacturer and Segment Designer from the early stages. The aim of this paper is to evaluate the influence of the segment lining design on TBM cost and performance, and to provide commentary on existing design guidelines to optimize lining and TBM procurement.

Elisa Comis

Bio

Elisa Comis, Project Engineer, has worked with The Robbins Company since 2010 on tunnel projects around the world. Comis earned a master’s degree in Mechanical Engineering in 2005, and began her career in tunneling in 2007, working as the SELI Plant Manager for the Mavi Tunnel in Turkey. She then worked in the field at projects in Hong Kong and Ethiopia with SELI before making the switch to Robbins. In her time at Robbins, she has worked on the AMR Tunnel in India and served as Project Engineer in a number of tunnels in Turkey, Russia, Australia, and the USA. Her most recent project is for the Gemeinschafts Kraftwerk Inn (GKI) Project in Austria.

Authors

Paolo Cucino, Dimitri Rizzardi, Luca Schiavinato, Alberto Meda

Abstract

Fiber reinforcement is increasingly used in civil works to strengthen materials which otherwise possess a brittle failure mode. In mechanized tunneling, precast concrete lining design and reinforcement dimensioning is generally driven by ram forces during TBM advance and results in a considerable amount of localized reinforcement. This paper describes the design of two sets of precast concrete lining of approximately 10m diameter which differ for segment geometry and number of rams. The paper highlights how the use of steel-fiber reinforcement to resist ram thrust forces, results in advantages and economies not restricted to TBM advance stage, i.e. easier production and assembly of the conventional reinforcement cage due to simpler geometry, and higher performance during handling and positioning.

Paolo Cucino

Bio

Working in strict collaboration with SWS engineering S.p.A., a Civil Engineering Company based in Trento, Italy. Core business of the company is mechanized tunneling, highway and railway infrastructures design. In SWS is Head of Geotechnical and Tunneling Office where he developed a great experience in large projects like the Brenner Base Tunnel, Underpass of High speed railway of Florence and the enlargement of highway tunnel M. Domini (enlargement of an existing highway tunnel ensuring regular traffic during work execution). As member of some of the most influential Tunneling and geotechnical associations, he published a numerous papers related to the tunneling.

Authors

Vassilis P Marinos, P. Fortsakis, G. Prountzopoulos

Abstract

The description of tunnel behaviour is fundamental information towards the design, the excavation and the definition of the support measures in tunnelling. The understanding of the potential failure mechanism enables the selection of the appropriate design parameters and the definition of the support principles. The research, in the framework of the specific paper, is based on the analysis of design and construction data from 62 non-urban tunnels of Egnatia Highway in Northern Greece. Within this framework, a standardization of the geotechnical behaviour of rock masses, called Tunnel Behavior Chart, is presented. The paper focuses on the application of this tunnelling behavior classification to several rock mass types of flysch formations, ophiolites, gneiss and limestones, presenting their distinct geotechnical characteristics. Finally, support principles for the principle behaviour types are proposed, based on the experience of this tunnelling practice.

Vassilis P Marinos

Bio

Dr. Vassilis Marinos has a bachelor of Geology, an MSc in Engineering Geology with Distinction, DIC at Imperial College and a PhD in geotechnical engineering. He is Assistant Professor of Engineering Geology in the Aristotle University of Thessaloniki, while he has 61 papers and participated in 15 granted research programs. Professionally, he has been consultant in highway tunnelling works, Metro projects, in design companies of tunnels and large dams and lead engineering geologist in Natural Gas Pipeline project.

Dr. Marinos was awarded with an Honorary Mention for the Richard Walters prize (IAEG prize). The evidence of esteem and external visibility are the 150 citations of his research work, the inclusion in design specifications of Metro works in Greece with sections of his research work and use of parts of his work (GSI systems) in the design of large engineering works internationally. Dr. Marinos is a member of IAEG, ISSMGE, ISRM.

Authors

Marko Žibert,Mark Clarke

Abstract

BIM – building information modelling is in its essence an invention created over the years by the architects therefore designed to the architect’s needs. However, what else is a tunnelling engineer if not an architect shaping the ground collaborating/leading a group of many design disciplines and other providers to create a functional and safe “building� in a safe way? It is a common nightmare when a tunnelling engineer has to decide on important design issues using data from different providers, different tools during design and moreover during construction. A model backed up by a structured database of graphical and non-graphical information is a dream becoming reality. As BIM is designed around building industry, it has to be rethought and reshaped for tunnelling industry. The paper shares experience of all parties involved in reshaping BIM processes & modelling to their needs of building Karavanke tunnel as one of major large trans-alpine tunnels.

Marko Žibert

Bio

Marko completed the study of civil engineering at the Faculty of Civil engineering in Ljubljana. His professional career began as a structural engineer. In 2002, he joined the team Elea iC, where he worked as lead designer in civil works and in 2004 received the award for best steel structure at the European Convention for steel structures - ECCS. Later he took over the development and management of tunneling department and now for almost a decade he is working as a partner in Elea iC.

His tunneling portfolio stretches from very demanding geotechnical tunneling applications both at domestic market to stints on international market such as Portugal, Bosnia, Sweden, Germany, Greece, Austria and Italy. He has received awards for his achievements, is a member of several professional bodies and regularly attends professional conferences, where he presents topics related to the construction and design of tunnels as well as tunnel safety.

Authors

Öncü Gönenç, Takaya Takimoto, Takayoshi Otsuka, Kazuto Fujii, Taher Elsamni

Abstract

This paper discusses a very unique research including design and testing on the compressible type gaskets for steel segments, which has not been studied much in the field of the TBM tunneling. Over the course of developing the design of segments of steel rings or flexible rings of the bored tunnels for Eurasia Tunnel, it was discovered that gaskets do not have sufficient space to expand upon compression during the assembly of the segments if the original concrete segment groove design is followed. It was also discovered that the gasket profile adapted in the corners of the segments have a critical role in the water tightness performance. This research covers an evaluation on how different assembly methods for steel rings impact the performance of the gaskets through testing and with specific examples from Eurasia Tunnel in Istanbul, Turkey.

Öncü Gönenç

Bio

Civil Engineer, BSCE, MSCE

Technical Office Chief of Istanbul Strait Road Tube Crossing Project

Civil Engineer with 12 years of structural design and underground construction experience. Mr Gönenç is focusing on advanced applications of new underground technologies and their implementation in actual projects. His works include design interface and coordination and technical management including specifications and methodology preparations for underground structures with emphasis on bored tunnels.

Authors

Satoshi Honda, Toshinori Takahashi, Hiroyuki Itoi, Mitsuru Shimizu

Abstract

Railroad and road grade-separation is one of the effective means for settlement of traffic congestion in urban-areas. Tokyo-Met. organization is making a new road in Shinagawa-ku, and East japan Railway Company was contracted to design and construct the intersection part of the Tokaido-shinkansen and Yokosuka Line. In this work, we constructed a box culvert for a two-lane road underpass crossing railroads with distance fewer than 400mm to pier of Tokaido-sinkansen's viaduct. Constructing structures near high service frequency railroads come with very high degree of difficulty.

The main features are as follows:
(1)We adopted "JES(Jointed Element Structure) Method" to reduce the displacement of pier. JES Method uses small section steel elements with original joints to construct a box culvert.

(2)We examined the displacement of structures in advance by FEM analysis to confirm the safety of train operation and decided the management value of displacement during the construction period.

Satoshi Honda

Bio

Authors

Heiner Sander, Arman Farajollahi

Abstract

The Cooper Hospital located in 1 Copper Plaza, NJ required designing underpass tunnels to connect the existing parking lot to the hospital building crossing under the Interstate I-676. The highway in this area is a concrete highway with an asphalt overlay. The tunnels would cross under three PATCO commuter train tracks and maintaining continuous service of all tracks during construction is critical. Because of very shallow cover over the underpass tunnels, several options including Sequential Excavation Method, Box jacking, and Tunneling with Steel Pipe Support were considered. This paper summarized applications of these tunneling methods and their advantages and disadvantages including constructability, risk of ground movement, cost and application limits in the USA as a guide to selection of the best technical approach for implementation on similar projects.

Heiner Sander

Bio

Heiner brings more than 38 years of experience in project management, design and construction management of tunnels and underground projects. His extensive background in the application of NATM (New Austrian Tunneling Method, also known as SEM - Sequential Excavation Method) and the application of ground support systems using shotcrete, rock bolts and lattice girders, including the geotechnical instrumentation (monitoring, interpretation and evaluation) of subsurface measurements to define the rock classification and appropriate support measures for subsurface structures. Heiner worked on major construction sites in Austria, Germany, United Kingdom, Canada, Turkey, Mexico, Honduras, Guatemala, Denmark and the United States of America.

Authors

Yang Jiang, Matt Bowers, Sanja Zlatanic, John Anderson

Abstract

The 8.5-mile Crenshaw/LAX Light Rail Transit (LRT) line will connect the existing Metro Green Line to Expo Line near Los Angeles International Airport (LAX). The segment includes three complex underground stations: Vernon, MLK, and Expo, which will be constructed using cut and cover methods. Being located at one of the most seismically active metropolitan area in the country, two-level seismic performance criteria were adopted with specific performance objectives for each level. The stringent performance objectives included limitations on the location and extent of damage, so that damage is easily accessible and readily repaired. Seismic design of major structural elements was based on 3D seismic demands that account for the complex geometry, nonlinear structural behavior, and soilstructure interaction effects. Seismic performance objectives were evaluated through a combination of force-based and performance-based design checks. Challenges in accommodating construction means and methods are highlighted as well as their impact on the seismic design.

Yang Jiang

Bio

Yang has more than 23 years of experience on a wide variety of bridge and underground projects. Yang has led and performed design, analysis, review, and independent check for many types of bridge and underground structures. In recent years, Yang has focused on underground projects and built considerable experience in underground transportation structures including Crenshaw/LAX Transit Corridor Design-Build Project, the iconic Istanbul Strait Road Crossing in Istanbul, Turkey, and world's largest bored tunnel in Seattle.

Authors

Raymond E Sandiford, Taehyun Moon

Abstract

Superstorm Sandy (Sandy) caused sea water inundation in many tunnels in New York City in 2012. The effects of this unforeseen loading condition were analyzed. The inundation resulted in two distinct stress changes to the tunnel structures. The first stress change was water pressure on the inside face of the tunnel lining. The second condition related to the change in buoyancy of the tunnels. In areas where the tunnels were supported on rock and an adjoining area supported on soft soil, overstress issues arose. Numerical analyses were performed to assess the structural impacts of the tunnel water inundation; especially stress changes due to internal pressure as well as changes resulting from the buoyancy effects. The paper will discuss the assessment process and its results; it will demonstrate that the change in internal pressure were of little consequence, however the change in buoyancy resulted in significant increases in bolt stresses.

Raymond E Sandiford

Bio

Ray has more than 30 years of design and construction experience in major complex transportation and infrastructure projects including: tunnels, bridges, complex underground projects, highways, airports, buildings and waterfront facilities. He received his M.S. in Civil Engineering from Columbia University and his B.S. in Earth Sciences from SUNY Stony Brook. He is a licensed Professional Engineer in the sates of NY, NJ and MD.

Authors

Mahmoud Sepehrmanesh, Taehyun Moon

Abstract

This paper presents the impact of tunneling and its associated risks on pile foundations located in the influence zone of tunneling operation. Tunneling in proximity of pile foundations introduces deformations in piles and in turn induces additional axial and bending forces. In modern mechanized tunneling, ground convergence is controlled through balancing the earth pressure at the tunnel face as well as applying pressurized bentonite through the shield. Reducing ground deformation can consequently lower the additional deformations and forces developed in the pile foundation and lessen the associated construction risk. In this paper, comprehensive detailed finite element modeling was performed to quantify the effect of the different parameters on induced forces in piles. Finite element models took into account the nonlinear behavior of soil and pile-soil interface. The modeling results are of practical importance in risk evaluation of tunneling in vicinity of pile foundations.

Mahmoud Sepehrmanesh

Bio

Mr. Mahmoud Sepehrmanesh is a Tunnel Design Engineer at AECOM specializing in tunnel and underground structures. Mahmoud has a master in Geotechnical and Geomechanical Engineering and more than 7 years of work experience. His technical expertise is mechanized tunnel engineering, numerical analyses in geotechnical related issues. He has been involved in design of several transit, water and wastewater tunnel projects in North America.

Authors

Naotoshi Yasuda

Abstract

Some mountain tunnels in Japan have experienced significant damage in recent earthquakes, and these damaged tunnels often have voids behind the lining. To evaluate the effect of the void for seismic wave, three dimensional behaviour of a cylindrical tunnel with voids behind the lining under an oblique incidence of seismic wave are theoretically derived. The surrounding ground is taken as an infinite, homogeneous, isotropic, and linear elastic medium and the lining is treated as a linear elastic shell. The volume of the void is ignored, and the void is treated as partially non-contact boundary between the lining and the ground. The substructure method and Fourier series representation are used to derive general solutions. Numerical results show that stress states of the lining is little affected by the void under seismic loading. Therefore, we can predict that damaged tunnels have already had large stress concentration before earthquake especially by the void.

Naotoshi Yasuda

Bio

Naotoshi Yasuda was born on March 2, 1987 in Wakayama, Japan. He got doctoral degree of engineering in Kyoto University in 2014. He is now the assistant professor at Kyoto University Graduate School of Engineering Department of Civil and Earth Resources Engineering. His research interests are related to tunnel maintenance and seismic design of tunnel, and he is familiar with elastostatics and elastodynamics. His previous researches are mainly related to seismic response of the underground structures, and they are based on the analytical solutions, which are expressed as the sum of the deformation mode. His motto is "simple is best". Now, he has interest in effect of rockbolt for weak rock and defective detection of tunnel by laser equipment.

Authors

Teoh Yaw Poh, Qiao Yue Tung

Abstract

The Singapore Government has announced plans to significantly expand the coverage of Singapore’s rail network within a 10-minute walk of a rail station by 8 in 10 households. With such rapid expansion of the rail network in our already densely built-up city, more tunnelling works will be carried out in close proximity to existing buildings. Such tunnelling works are likely to impose higher risk to nearby buildings, especially for tunnels in mixed ground conditions. This paper highlights the control framework implemented by the Building and Construction Authority of Singapore to ensure safety of the public and the tunnelling works. Among other measures, the framework requires professional engineers to assess the need for proactive measures, the adequacy of the site investigation and the monitoring requirements to ensure safety. Lastly, the effectiveness of this control framework will be shared via several case histories of tunnelling beneath buildings.

Teoh Yaw Poh, Qiao Yue Tung

Bio

Teoh Yaw Pog

Dr Poh is a Deputy Director with the Building and Construction Authority which oversees and administers the regulatory framework on building structure safety in Singapore. He is a geotechnical specialist with over 18 years of practical experience. He has authored over 15 publications in geotechnical design and construction including those published in international peer-review journals and conferences.

Qiao Yue Tung

Ms Tung is an Executive Engineer with the Building and Construction Authority in Singapore. She graduated with Bachelor of Engineering (Civil Engineering) with first class honors from the National University of Singapore.

Authors

Erik S Bernard

Abstract

Seismic resistance is an important aspect of Reinforced Concrete design in many parts of the world subject to the risk of earthquakes. To provide enduring load capacity during a seismic event, steel reinforcing bars within a reinforced concrete section need to be confined against buckling in compression, and concrete within the section needs to be restrained against loss from the section. The traditional approach to achieving these goals has been to include numerous stirrups at close centers along all RC members, but this approach is expensive and time-consuming to effect. It can also lead to highly congested reinforcement cages that make it difficult to fit joint tubes and M&E fittings when constructing tunnels.

An alternative to the use of closely spaced stirrups is the inclusion of macro-synthetic fibers in the concrete. The present paper describes a large experimental investigation in which 78 beam-columns made with steel reinforcing bars and either plain concrete or macro-synthetic FRC were tested to destruction. The beam-columns were subjected to reverse-cycle simulated seismic loading in accordance with ACI 374, and results were compared in terms of residue load carrying capacity at large levels of deformation. The data have indicated that as little as 6 kg/m3 of Barchip BC54 macro-synthetic fiber can provide resistance to reverse-cycle loading equivalent to some seismic code requirements based on stirrups.

Erik S Bernard

Bio

Dr Bernard is a research engineer and owner of TSE Pty Ltd, a firm based in Sydney, Australia, specializing in research and development related to fibre reinforced concrete. He has PhD in structural engineering, has authored over 100 papers on various aspects of structural engineering and concrete technology, and has chaired several international conferences on shotcrete. He is chair of the Australian Shotcrete Society, vice-animateur of ITA WG12 on shotcrete, TG chair within ASTM sub-committee C9.42 on FRC, and is a member of RILEM TCC on creep of FRC.

Authors

Atsushi Kusaka, Kosuke Kawata and Nobuharu Isago

Abstract

Rock tunnels suffered severe damages from recent large earthquakes in Japan, despite the empirical knowledge that tunnels are much stronger than surface structures. Seismic design for rock tunnel has therefore become a fascinating subject for many tunnel engineers. However, even basic behavior, including deformation mode and loading magnitude for hard-rock TBM tunnels and conventional ones during earthquake, has not been fully understood due to lack of actual seismic data; while EPB and slurry TBM tunnels gradually take account of seismic design in Japan.

This study conducted a dynamic measurement in an actual road tunnel constructed in rock mass. The strongest aftershock of "The 2011 off the Pacific coast of Tohoku Earthquake" occurred during the measurement, providing precious data to examine deformation mode and strain magnitude of the tunnel. Considering the acquired data, numerical analysis was also performed to calculate loading magnitude to cause fatal fracture of tunnel lining during earthquake.

Atsushi Kusaka

Bio

Senior Researcher in Tunnel Research Team, Public Works Research Institute (PWRI), Japan

Authors

Alessandro Damiani

Abstract

The new tunnels of the Copenhagen "Cityringen" will be excavated, in Kongens Nytorv, over the existing M1 and M2 metro lines. After the intersection, the tunnels will underpass the historical building of the Magasin du Nord and adjacent masonry buildings with a minimum cover of about 5.80 m. The tunnels have an internal diameter of 4.9m and are being excavated through Earth pressure balanced Tunnel Boring Machines in mixed face.

The Magasin du Nord estate is characterized by a very complex structure, with different blocks built in different times. An assessment of the condition of the building and its sensitivity to tunnelling-induced ground movements has been conducted through a fully coupled soil-structure interaction analysis; by the results of this analysis, mitigation measures have been designed. Most part of the building will be subjected to constant monitoring; displacements recorded will be compared with numerical results.

Alessandro Damiani

Bio

General Director, Technical Director and Partner of Lombardi Ingegneria S.r.l., Milan (I)

Authors

Hengyang Hu, Yong Yuan, Xiewen Hu

Abstract

At present, response displacement method has been widely used in underground structures design. However, there aren't not enough research projects about response displacement method for underground structures subjected to different period seismic ground motions. Thus the researches on the influence of different period seismic ground motions can't be well developed. The transverse sections of two circle tunnels under different geological conditions are used to analyze and evaluate the applicability and accuracy of the response displacement method. The seismic response of the tunnel by using dynamic time-history analysis will be given as a reference standard when assume structure properties and buried depth are same. According to the comparison of the internal force responses and the displacement responses of the two tunnels under different period seismic ground motions, the paper concludes the applicability and accuracy of the response displacement method.

Hengyang Hu

Bio

Master Degree Candidate, Engineering, September 2013 until now Tongji University, Shanghai, China Advisor: Yong YUAN

Authors

Ying Cui, Kiyoshi Kishida, Makoto Kimura

Abstract

During the construction of the Bullet Train lines in Japan, several shallow tunnels were excavated in unconsolidated grounds using conventional tunneling methods. In order to prevent ground and tunnel settlements and to ensure the stabilization of the cutting face of the tunnels, a previous ground improvement auxiliary method(pre-ground improvement method below) was adopted in the above-mentioned fields, and the tunnels were excavated successfully. However, there is a possibility of the occurring of stress concentration around improved area due to the high stiffness and weight of the improved ground, during earthquake. In this study, therefore, 2D seismic elasto-plastic finite element analyses are carried out to make clear the seismic behavior of shallow overburden tunnels that adopted pre-ground improvement method. Analytical results indicate that, stress concentration can be seen around the improved area, and the aseismic capacity of the tunnel become lower when the improved area are narrow than a certain value.

Ying Cui

Bio

Associate Professor, Department of Civil Engineering, Meijo University

Authors

Kosuke Kawata, Nobuharu Isago, Atsushi Kusaka

Abstract

Strong earthquakes occur in a short span of time in Japan and some rock tunnels suffered severe damages on their permanent lining. Many road tunnels which were constructed by conventional steel arch support and timber lagging method exist in Japan and these need risk mitigation measures against earthquakes from our empirical knowledge. Many reinforcing measures for deformed tunnel that may be effective against earthquakes are developed, however, their behaviors during earthquakes are not fully understood.

In this study, static loading tests and numerical analysis simulating a loading condition during earthquake were carried out to clarify the effect of countermeasures. Load-bearing performance of tunnel structure facilitated by installment of inverted arch is found, however the weakness of structure may be brought by a joint between inverted arch and sidewall. Rockbolts and carbon fiber sheet are potentially to mitigate the risks of collapse of lining by the force from an earthquake.

Kosuke Kawata

Bio

Research Specialist in Tunnel Research Team, Public Works Research Institute (PWRI), Japan Professional engineer, Japan

Authors

Duhee Park, Jae-Kwang Ahn, Jin-Kwon Yoo, Jungseon Park

Abstract

We perform pseudo-static and dynamic analyses of cut-and-cover tunnels to investigate their performance under intense seismic loading. The analyses show that single tunnels are significantly more resistant to earthquake induced shear deformation compared to double tunnels. Double tunnels may suffer considerable structural damage, especially at the center column which typically have a smaller section. The difference between a pseudo-static and dynamic analysis is shown to be not significant and within 30 %. We show that the difference is dependent on the flexibility ratio and the wavelength of the tunnel. We conclude that in most cases, a pseudo-static analysis is sufficient for evaluation of the seismic performance of cut-and-cover tunnels.

Duhee Park

Bio

Associate professor University of Hanynag, Department of Civil and Environmental Soeul, South Korea

Authors

Behzad Khorshidi

Abstract

The Port Mann Tunnel involves a 1km long tunnel beneath the Fraser River in BC at depths of up to 60 m below ground which is the highest pressures for an EPB tunnel in North America to date. A welded 2.44m diameter steel pipe with 1 inch thickness is installed by pipe carrier within 3.15m precast segmental lining of the tunnel and later the gap between steel pipe and segmental lining is grouted in 5 stages which provides buoyancy loading and temperature difference upto 80 degree Celsius which applies significant thermal loadings on the steel pipe as well as reaction loadings on the steel support posts between them. The steel pipe is modelled by STAAD PRO program and thermal and buoyancy loadings are evaluated to ensure about acceptable stresses and deflections at each stage. The reaction loadings on the supports are checked as well to avid any punching on the segment lining and steel pipe. All calculated effects are compared by actual measured values.

Behzad Khorshidi

Bio

Dr. Behzad Khorshidi is a professional engineer with over 15 years’ experience in wide ranging aspects of geotechnical and structural engineering including design and construction of shafts, tunnels, foundations, retaining walls and other industrial and general structures. Experienced in the engineering management and design management, technical evaluation, preparation of designs and shop drawings and construction details, value engineering, specifications, building codes and standards, construction method statements and procedures, construction planning and budget analysing as well as quality control and managing of the survey plans and activities.

Authors

Scott W Lewis

Abstract

The occurrence of the 2014 South Napa Earthquake in a region with over 100 tunnels for wine caves presents a unique opportunity to evaluate the seismic performance of tunnels. The authors designed over 50 constructed wine caves in the Napa and Sonoma Valley regions that experienced ground motions during this earthquake. The authors will expand data and evaluations by Kaneshiro (2000) and Hashash and others (2001) and further demonstrate good seismic performance of tunnels. The seismic performance of wine barrel racks and other structures in the caves may give insights on the characteristics of ground motions.

The authors will observe tunnel conditions; interview personnel; evaluate ground motions at tunnels, as-constructed support and tunnel dimension, and tunnel condition; and, develop any correlations. Our data and evaluations will add value to the underground community for assessing reliability of tunnels subjected to earthquake ground motions.

Scott W Lewis

Bio

Mr. Lewis is a Principal Engineering Geologist and Tunneling Consultant with Condor Earth Technologies, located in Sonora, California. He has worked on over 250 tunneling projects, including feasibility, design and construction of over 200 wine storage caves and underground wineries throughout California and several western states.

Mr. Lewis has over 30 years of experience in geologic investigations and construction of tunnels, dams, structural foundations, slope stabilization, landslides and other geologic hazards. He has served as the project director, manager and/or principal investigator on numerous slope evaluation, tunnel feasibility and construction projects. His specialty is in coordinating and performing field investigations, tunnel evaluation, preparation of construction plans and specifications, and construction management and field engineering.

He received a Bachelor of Science degree in Geological Sciences from the University of Southern California and a Master of Science degree in Geosciences from the University of Arizona.

Authors

Freddy Duran Cardenas and Junji Kiyono

Abstract

It is well known that in large population cities located in earthquake-prone countries like Japan, the underground structures have become critical to alleviate the transport and also to expand underground lifeline systems such as water, sewage, electrical and gas pipeline systems. Thus, it is necessary to assess the seismic vulnerability of such underground structures. For this purpose, a dynamic finite element analysis of a shield tunnel of 16m diameter embedded in two ground conditions: soft ground and stiff ground, for both cases, the tunnel is subjected to two types of strong ground motions represented by the acceleration records of the 1995 Hanshin Awaji Earthquake and the 2011 Tohoku Earthquake. is presented herein, in which the critical point will be the evaluation of the influence of ground deformation on the seismic response of the shield tunnel for the two different ground conditions as well as for the two types of strong ground motions above mentioned.

Freddy Duran Cardenas

Bio

The presenting author’s obtained his Master Degree in 1996 and Ph.D degree in 1999, both from Kobe University, Japan. He worked in Japan in the structural engineering field at the academic, research and consultant levels. From April 1999 to end of March 2000, Freddy Duran C. worked as research associate at Nagoya Institute of Technology, Japan, conducting research on fracture in the vicinity of interface of dissimilar materials, and fracture phenomena due to thermal stress and deformation of bedrock. Between 2000 and 2003, he worked as research associate at Kyoto University, conducting experimental evaluation of high strength concrete properties. Between 2003 and 2004, he worked as consultant at CTI Engineering Co.Ltd in Osaka, Japan. From June 2004 to March 2009 he worked as research engineer at Kyoto University conducting earthquake response analysis of neighbour tunnels. From 2004 to end of March 2014 he worked as associate professor at Kyoto University conducting research on dynamic soil-structure interaction effects in underground structures during strong earthquakes.

Authors

Jong ho Shin

Abstract

Demands of urban underground railway service often requires to construct additional metro or rapid transit tunnels beneath or adjacent to the existing railway tunnels. In urban areas, however, railway tunnels cause ground-born noise which often gives rise to strong anti-railway or anti-tunnel movements from citizens. Moreover, dynamic structural interaction between tunnels during operation is another important issue.

Thus the evaluation of dynamic effects between tunnels becomes an important matter in urban tunneling, particularly in the case of tunnel construction beneath the existing tunnels. However, the interaction problem between tunnels is so complicated as not to evaluate easily, and has not been much studied yet. Therefore, the dynamic effect between tunnels could not be appropriately considered in the planning and design phase of tunnels.

In this study, the interaction between existing and newly constructed tunnels is investigated by experimental and numerical methods. Particularly, the amplification effect on the existing tunnel due to a newly constructed tunnel is concerned. It is found that the construction of a new tunnel beneath the existing tunnel has increased structural behavior significantly. Particularly at the ground surface the amplification of ground-born vibration has increased by about 30% comparing to that from a single tunnel. In this paper, finally a method to model and predict the interaction between tunnels will be proposed for the preliminary evaluation of dynamic amplification effect between tunnels.

Jong ho Shin

Bio

Prof. Shin currently holds professorship at the Konkuk University, Seoul, Korea. He studied at Imperial College, London, UK(PhD) and the Korea Advanced Institute of Science and Technology(KAIST, MSc). He started his career as a civil engineer in Daewoo Engineering Company in 1985 and joined in Seoul Metropolitan Government(SMG) in 1988. During 17 years of SMG he had involved in several large-scale construction projects. He has taught and researched at the Konkuk University since 2004. .His research has been focused mainly on tunneling, particularly on the structural and hydraulic interaction problems in tunnels, and identified the mechanism of long-term hydraulic deterioration of underwater tunnel. He has published more than 50 papers.

Authors

Jon Hurt, Joe Carvalho

Abstract

The shales of the Greater Toronto Area (GTA) have been known to experience time-dependent deformations; those initiated by excavation-induced stress relief which progress with time as a function of rock porewater salinity, access to freshwater (or air) of lower salinity, clay and calcite content, and the buildup of swelling pressures within the rock mass. These deformations can induce long-term pressures on shaft walls and tunnel linings, especially if the permanent works are constructed soon after excavation, with very little time delay. This paper presents measurements of time dependent deformation of recent shaft and tunnel projects constructed in the GTA, comparing them to closed-form and numerical predictive models. The key input parameters for the numerical predictive model are critically assessed. Projects which are discussed include the Billy Bishop Airport Pedestrian Tunnel, Hydro One Midtown Tunnel and Hanlan Feedermain (Contract 3).

Jon Hurt, Joe Carvalho

Bio

Jon Hurt, PE, CEng MICE is the leader of Arup's Tunnel Practice in the Americas, and the global leader for the Tunnel Skills Network, responsible for providing resources, training and knowledge sharing within Arup's tunneling community. He is a project manager and tunnel engineer with a wide range of experience in the management, design and construction of major tunneling projects.

Co-presenter Dr Joe Carvalho, PEng, is a Principal of Golder Associates in the Mississauga office in Canada, and is a rock mechanics and fracture mechanics specialist with 25 years experience in the field. He is experienced in elasto-plastic, visco-elastic and poro-elastic analysis of stress, including tunnels for subway and hydroelectric developments. Dr. Carvalho also has extensive experience teaching and training.

Authors

Benedikt Grau

Abstract

In Crossrail's Farringdon station, compensation grouting was successfully utilised to mitigate the surface settlements induced by the tunnelling works. The main focus of this study was the platform tunnels, which were approximately 300m long each and were enlarged to platform size using sprayed concrete lining methods from the existing TBM running tunnels. The rear grouting injections were carried out at a typical distance of minimum 5m above the completed, fully strengthened shotcrete lining hence inducing some additional stresses. In-tunnel monitoring using surveying targets was performed systematically to ensure that no excessive distortion of the shell occurred.

3D finite element analyses were utilised to back calculate the actual "effective" pressure that was imposed on the completed shotcrete rings against the additional measured in-tunnel displacements due to the compensation grouting episodes. Additionally an assessment of the theoretical, "maximum" allowable grouting pressures that would lead to overstressing of the lining is presented.

Benedikt Grau

Bio

Authors

Martino Semeraro, Edoardo Misano, Alain Bochon

Abstract

The existing Underground Laboratory of Modane (LSM) is located close to the 13 km-long Fréjus Highway tunnel, at the French-Italian border. The extension of the laboratory is currently under study and consists in the construction of an additional 40m-long cavern, with a cross-section of 300m2 , and located parallel to the existing LSM, 50m apart from it. The new laboratory will be situated between the existing highway tunnel and its safety tunnel which is currently under construction, and it will be perpendicular to both tunnels. The average distance between the extreme end of the new LSM and the highway tunnel is about 25m. The cavern overburden is about 1800m and the excavation will be performed through schistose rocks, perpendicularly to the schistosity, from the safety tunnel towards the highway tunnel.

To evaluate the impact of the cavern construction on the highway tunnel, an investigation campaign based on in-situ and laboratory tests has been realized. The investigation program has been focused, among others, on the lining conditions of the existing tunnel and of the slab separating the road from the ventilation adit in the tunnel, and this in order to validate the considered lining thickness, its conditions and its state of stress.

The results have been used to calibrate the numerical models. Hence, FEM analyses have been carried out including the highway tunnel and the laboratory in order to assess the potential effects on the highway tunnel lining - which will remain under operation - and the excavation. A specific monitoring plan has been conceived to survey the tunnel convergences and the evolution of lining stresses during the excavation.

The paper describes the approach followed to design the new cavern and illustrates the main results.

Martino Semeraro

Bio

Martino SEMERARO is a tunnel and structural design engineer at SYSTRA since 2008, where he works on projects concerned with the various stages of railway infrastructure design. As graduate in Civil Engineering, he has worked for the design and supervision on various tunneling projects, including railway and metro tunnels. During the 8 years of profession, he has experience in underground structures, including calculations with numerical modelling, methods, soil treatments, coordination of design and construction follow-up of underground works. He has been involved in tunnelling execution or studies in several countries (Italy, France, Algeria, Azerbaijan, Bulgaria, Saudi Arabia, Vietnam etc.) both for mechanized and mined tunnelling. Ha has a practical knowledge of Eurocodes ACI, AASHTO codes, recommendations on Fibre concrete and safety railways codes. He is responsible for tunneling and ancillary works of the extension of metro line 11 in Paris.

Authors

Matthew R Crow, Yiming Sun, John Yao, Martin B. Hudson, John Waggoner, and Roozbeh Mikola

Abstract

The Wilshire Grand Redevelopment project includes construction of a 73-story tower in downtown Los Angeles that will be the tallest building in the western United States. Construction of the tower's foundation required excavation up to 28 meters deep. The shoring on one side of the excavation needed to be within about 1.8 to 3.0 meters horizontally of a 122-meter-long section of the Los Angeles Metro's Red Line subway tunnel. The shoring system for the deep excavation was designed to minimize the effects of tower construction on the existing tunnels so that normal rail operation was maintained during construction. This paper presents the numerical modeling performed to evaluate the effects of excavation on the tunnel lining and rail operations, tunnel instrumentation, and the recorded response of the tunnel structure during excavation. With increasing urban redevelopment in major cities, the project is a valuable case history for excavation adjacent to existing tunnels.

Matthew R Crow

Bio

Mr. Crow is the Director of Project Engineering for tunnels at LACMTA responsible for the engineering aspects of project delivery relating to tunneling and underground construction. Recent rail Transit Projects that Mr. Crow have been involved in include Crenshaw LAX Corridor, Regional Connector Transit Corridor and the Purple Line Extension. Highway Projects include SR-710 Environmental Study, including option for a 10-km-long, twin 18-m-diameter freeway tunnel. He is also responsible for management of impacts by third party development on tunnels, development of Metro Standard Specifications for Design-Bid-Build and Design-Build Projects, and investigation and development of water and hydrocarbon leak mitigation measures in existing tunnels. Prior to LACMTA, Mr. Crow served as senior project or construction manager on major projects including Waller Creek Tunnel in Austin, Texas, ECIS/NEIS sewer tunnels in Los Angeles, London Underground including Central Line and Jubilee Line Extension, and numerous other underground projects in the U.S. and U.K.

Authors

Vincius Resende Domingues, Bernardo Cascão Pires e Albuquerque; André Pacheco de Assis

Abstract

The increasing demand for underground works in ur ban centers, and in particular the need to build undercrossing tunnels, requires constant evolution in building techniques in order to achieve success and safety. In the case of Brasilia, capital of Brazil, in order to preserve an important avenue (Eixo Monumental), where are located many historical monuments, the construction of a tunnel was envisioned as an alternative to interconnect the National Stadium to the Convention Center Ulysses Guimarães. The excavation design displays a coverage smaller than one diameter, height of 7.5 m, width of 9.0 m and length of 25 m. In order to enable a negligible influence on the avenue's usage, the structure is designed as a portico system composed of crimped juxtaposed pipes. In this context, this study presents the portico analytical solution with the assistance of the software Mathematica and a numerical solution using the software ABAQUS.

Vincius Resende Domingues

Bio

The presenting author is a civil engineer graduated at University of Brasilia (UnB) and Master's student at the same place. He has done research in Fractional Calculus and Fractals applied to Advection-Dispersion problems in contaminant transport in porous media as well asin the Finite Element Method implementation of Microtruss Model to simulate crack opening on concrete beams. His Master's thesis is the application of Discrete Element Method to model cyclic loading on foundations of wind turbines in sandy soils. He has also worked at UnB's Architecture and Civil and Environmental Engineering Junior Enterprise, Concreta Consulting & Services, as a business manager and as a designer of foundations and structures.

Authors

Hong Yang, S. Von Stockhausen, K. Huynh

Abstract

The Regional Connector Transit Corridor is a 1.9 mile long light rail transit project in downtown Los Angeles, California. The project includes approximately 4,930 feet of twin bored tunnels together with a mined crossover cavern, 3 deep stations and other cut-and-cover structures. The bored tunnels are excavated using a pressure face tunnel boring machine through the extremely weak rock of Fernando Formation and alluvium. The tunneling will be performed in close proximity to a large number of existing structures, including the existing Metro Red Line tunnels with as little as 6 feet of separation. Thus the assessment of the tunneling effect on these structures and design of the instrumentation and monitoring program becomes an essential part of the project design. This paper describes how geologic information, as-built information and previous construction experience were integrated to assess ground movements induced by the bored tunnel construction and to estimate the corresponding structure’s response; and how the results were used to inform the need for and extent of mitigation prior to tunneling as well as design of the extent of instrumentation and monitoring program required.