Innovative SOE Solutions for Shaft Construction: Getting to Depth With Diaphragm Walls at Westerly Storage Tunnel

The Westerly Storage Tunnel (WST) Project is part of Project Clean Lake, the Northeast Ohio Regional Sewer District's program designed to reduce pollution in Lake Erie by 4 billion gallons over the next 25 years. When completed in 2020, WST will be nearly 2 miles of 25-ft diameter tunnel installed 200-250 ft below ground. The storage tunnel will manage higher flow volumes, reducing stormwater influx in the combined sewer system and reducing overflow occurrences. The project required three deep shafts to access the tunnel, one each at the launch and retrieval sites for the TBM and a third for a vent shaft. Support of excavation for the access shafts was constructed utilizing unreinforced diaphragm walls. This innovative, value-engineered alternate significantly reduced risks associated with traditional secant piles combined with a rib and liner plate system. Implementation of the diaphragm wall technology resulted in a water tight, continuous shaft keyed into rock. This case study and presentation will examine the design, methodology, installation approach, and challenges unique to each deep shaft.
About Jewels Stover

Jewels Stover is a Project Manager for the Major Projects Division of Nicholson Construction. She's been building complex projects in the geotechnical construction industry since 2007. Jewels excels at problem solving and building strong relationships with her clients, facilitating positive outcomes on even the most challenging projects. Wildly passionate about diaphragm walls, Jewels and her team have recently completed what are known to be the largest and smallest diameter diaphragm wall shafts in the US.

The Three Rivers Protection & Overflow Reduction Tunnel (3RPORT) – Design Challenges of the Launching of Pressurized Slurry TBM
Speakers: Roberto Schuerch, Pini Swiss Engineers, Zurich, ZH; and Emidio Tamburri, LANE Salini Impregilo, Fort Wayne, Indiana

Depending on the hydro-geological conditions and the overall project constraints, a tunnel boring machine (TBM) may be launched under high support pressure. The “pressurized” launching of a TBM represents a major design challenge particularly when the TBM is launched from a starter tunnel. The present paper focuses on the launching of the slurry TBM, named “MamaJo”, of the 3RPORT tunnel. The tunnel is part of the Long-Term Control Plan of the City of Fort Wayne (Indiana, USA) having the main goal to reduce the discharge of untreated Combined Sewer Overflows (CSOs and improve water quality in Fort Wayne’s CSO-impacted streams. The tunnel will have a length of about 7.5 km, an internal diameter of 4.87 m and will be excavated at a maximum depth of 60 m. Carbonate rocks are expected over the entire alignment. Due to the high rockmass permeability and high in-situ hydrostatic pressure at the tunnel elevation, the launching of the TBM has been designed taking into account a support pressure up to 6 bar. The paper presents the main geotechnical hazards for all launching stages as well as their impact on the design solutions. Finally, it summarizes the lesson-learned after the successful launch of the slurry TBM on April 2019. Particular attention is paid on the design of the launching chamber (incl. concrete plug) as well on the selection of the required TBM parameters.

About Roberto Schuerch
Dr. R. Schuerch has 10 years of experience in the domain of tunneling.  In 2016 he obtained the PhD title at the ETH Zurich on the subject of face stability in soft medium-low permeability ground. He was involved as consultant in major projects through the Alps and in several challenging tunneling projects in urban areas. Since 2016, he leads the Underground and Tunnels department of the Pini Swiss Engineers.

About Emidio Tamburri
Emidio Tamburri is a Construction Manager working for LANE Salini Impregilo at the 3RPORT Project (Three Rivers Protection & Overflow Reduction Tunnel) in Fort Wayne - Indiana, since April 2018. He is in charge for all the surface works, underground works and TBM operations. He has more than 15 years of experience in Tunnelling Projects around the world such as the Karahnjukar hydroelectric project in Iceland, the Metro C Line in Rome (Italy), STEP deep sewer tunnel in Abu Dhabi (United Arab Emirates) and Red Line North Underground of the Doha metro system in Qatar.

Design-Build Procurement of the Hampton Roads Bridge-Tunnel Expansion
Speaker: Martha Gross, Virginia Department of Transportation, Hampton, Virginia

The $3.86 billion Hampton Roads Bridge-Tunnel Expansion project in southeastern Virginia developed rapidly from concept selection in December 2016 to contract award in April 2019.  During this time, the Virginia Department of Transportation evaluated whether to structure the procurement as a privately-financed P3 or publicly-financed design-build; engaged regional stakeholders and the tunneling community to choose between immersed-tube and bored-tunnel construction alternatives; identified and retired cost-driving risks during procurement; and continuously refined the project scope, which ultimately entailed a 1.5 mile (2.4 km) four-lane tunnel crossing, 2.5 miles (4 km) of marine bridges, and 5 miles (8 km) of highway widening.

About Martha Gross
Martha Gross is Technical Director for the Virginia Department of Transportation at the $3.8 billion Hampton Roads Bridge-Tunnel Expansion.  She has been closely involved in all aspects of this project since joining VDOT in 2016.  Previously Martha worked as contractor, designer, and owner’s representative on major projects around the country.  She is a licensed civil engineer and holds advanced degrees from Penn State and Virginia Tech.

Multiple use of TBMs for Singapore’s ground breaking conveyance system of Deep Tunnel Sewerage System Phase 2
Speaker: Karin Bäppler, Herrenknecht AG , Schwanau, Germany

Singapore is regarded worldwide as a prime example of a future metropolis of global importance. Over the years, Singapore made good progress in tapping underground spaces, from utility to metro lines and roads, to meet the many and growing needs of urban environment. The next major milestone in subterranean development is the construction of the 50km long Deep Tunnel Sewage System Phase 2, which is an island-wide network of tunnels running across the southern and western areas of Singapore. The paper focuses on the groundbreaking new gravity-fed deep tunnels that will all be excavated by TBMs.

About Karin Bäppler:
Karin graduated as civil engineer from Technical University of Karlsruhe, Germany (today KIT) and completed post graduate studies at the Colorado School of Mines, USA. She joined Herrenknecht in 1997 and since then has specialized in geotechnology and R&D. Since 2008 Karin has managed the Geotechnical and Consulting department for the Traffic Tunnelling Division at Herrenknecht’s head office.

Owner’s Forum

Project Success from the Owners Perspective
Session Chair: Matthew Crow, Los Angeles Metropolitan Transportation Authority
Panel Moderator: Martin Knights, Martin Knights Consulting Ltd.
Panelists: Kathy Murtagh, Massachusetts Water Resources; Bryan Pennington, LA Metro; James Utterback, Virginia Department of Transportation; Steve Missanian, DCDA

Past President of the International Tunneling Association and Fellow of the Royal Academy of Engineering, Martin Knights, will be moderating a panel of senior executives from the Delta Conveyance Design and Construction Authority, Metro Vancouver and the Virginia Department of Transportation.  These Owners, located in different regions of North American are undertaking mega projects for diverse end uses that include significant elements of underground construction.  After brief introductions, the panel, in an interactive real time format, will discuss the salient issues that impact project success and what they see as critical success factors.  Questions will be posed by Mr. Knights that include audience input that facilitate the panel in sharing their extensive experience of delivering megaprojects to help the audience discern and understand what makes a project successful from the North American project owners perspective. 

The session will last about just under an hour. Panelists subject to change based on speaker availability.

Tunnel Demand Forecast Plenary Session
Session Chair:  Jonathan Klug, Vice President, David R. Klug & Associates

The Tunnel Demand Forecast session features presentations from various owners and engineers regarding upcoming projects throughout the US and Canada.  An overall update and summary of North American tunnel projects will also be given.  Some of the projects and programs to be discussed will include:

• MWRA Metropolitan Tunnel Program, Boston, Mass.
• DART D2 Subway, Dallas, Texas
• Sound Transit, Seattle, Washington
• Superconducting MAGLEV Project, Baltimore/Washington D.C.
• Canadian Upcoming Projects Update

Each presentation will last approx. 20 minutes with limited question and answer period to follow.  Presentation list is subject to change based.

Investment and Operation Cost Savings with Innovative Fire Life Safety Systems Design
Speakers: Daniel Fischer and Hans Haring, ILF Consulting Engineers

The paper considers project examples where cost savings have been achieved by developing different concepts for Fire Life Safety equipment.  In several case studies it will be demonstrated that due to an alternative approach during the design phase significant reduction in the cost of equipment and in some cases even construction costs could be minimized. The impact of optimized design to operation and maintenance cost will also be part of the investigation. Due to a well thought out ventilation concept intermediate vent shafts could be avoided or the intermediate ceiling was eliminated. Other examples point out how cabling cost or operation and maintenance cost can be reduced for tunnel lighting.

About Daniel Fischer:
Daniel Fischer started 2007 in ILF Consulting Engineers, based in Austria, as Electrical Engineer. In this time he was working for several transportation projects, as well as projects in the water & environment and power plant sector. His experience covers design, construction management and project management. Daniel was in charge of several projects in Europe, Middle East and Asia. It is planned that he will work in future in the United States for ILF.

About Hans Haring:
Hans Haring is the Project Development Director Tunnel systems and Fire Life Safety for ILF Consulting Engineers in North America. He is also responsible for the High Voltage Business Development Division for ILF in Europe.

Hans started his business career as an plumber apprentice 1980 and worked for several companies beside his mechanical and electrical studies till 2002. In 2002 he started in the ILF Consulting engineers group as a technical project expert for tunnel systems and waste water treatment plants. After 2 years of onsite commitment in the middle east, Hans became the head of the electrical and mechanical department in Austria. Hans started with a team of 12 E&M designers and had finally 43 technicians, project managers and onsite experts in his team when he handed over the department 2017 (now divided in an electrical and a mechanical department) to his colleagues Mr. Heis and Mr. Gertl (the 2 co-authors of this presentation). Hans is now responsible for all international fire life safety and high voltage projects and business development activities for ILF North America and ILF Europe.

Update on the VTA’s BART Silicon Valley Phase II Project Challenges to Urban Excavation through Chalk Formation Info
Speakers: Ronak Naik, Santa Clara Valley Transportation Authority, Santa Clara, CA and Anthony Bauer, HNTB, Los Angeles, CA.

About Ronak Naik:
Ronak Naik is a Transportation Engineer for the Santa Clara Valley Transportation Authority (VTA) with eight years of experience on public sector projects during the planning, design, and construction phases. He has been working on the VTA’s BART Phase II Extension project since the environmental clearance phase on conceptual design work, technical studies and third-party coordination.  He currently supports the Chief BART Delivery Officer on administration and management of the program including day to day internal operations, technical engagements with key stakeholders, and program controls.

About Anthony Bauer:
Anthony Bauer is the West Region Tunnel Practice Lead for HNTB. He specializes in the design, analysis and project management of tunnels and underground structures with project experience around the world. Currently he is serving as the Deputy Engineering Manager for the BART Silicon Valley project for the program management team.

Challenges to Urban Excavation through Chalk Formation
Speaker: Eric Wang, HNTB Corporation, New York, New York

Although chalk limestone is generally viewed as a favorable medium for tunneling, its engineering properties can present unique challenges to be considered in design and construction. Specifically, selection of excavation methods and support systems for tunnels beneath congested urban centers should account for the ground behavior of underground construction in chalk. Challenges presented by specific engineering properties and the associated construction requirements are discussed including potential geo-hazards such as low uniaxial compressive strength, methane gas, solution cavities, faults, slickensides and principal stress ratio. Case histories are shared providing lessons-learned on two continents regarding overcoming these challenges.

About Eric Wang
Eric is an Associate Vice President and East Operations Manager for HNTB's National Tunnel Practice with more than 30 years of experience. Past projects include MTACC's Number 7 Subway Line Extension, MTACC's East Side Access, NJ Transit's Trans-Hudson Express (THE) Tunnel, MTA Baltimore RedLine, Ohio River Bridges - East End Crossing Tunnel and DART D2. He is a licensed professional engineer in 6 states. Member of ASCE Geo-Institute's Underground Engineering & Construction Technical Committee.

Supporting Post-bid Change in Segment Design and Machine Launching Philosophies for the Bergen Point Outfall Tunnel, Suffolk County, NY
Speaker: Mahmood Khwaja, CDM Smith, Waban, Massachusetts

At more than 14,000 feet in length, the Bergen Point WWTP outfall tunnel was bid with a traditionally reinforced segmental lining, and with the boring machine to be launched from a shaft and starter tunnel, both using ground freezing to support respective excavations.  During construction, the contractor modified the segment design to use fibre reinforced concrete; submitted a substitution to modify the machine launching approach, such that the first 400 feet will be tunneled using a method traditionally reserved for micro-tunneling, thus accommodating the installation of the trailing gear without the need for a starter tunnel.  This paper provides a brief on the shift in, and the post-bid criteria development for, the segment design approach and the unique method for launching the slurry machine; evaluates the benefits and challenges related to these significant modifications to the original design; and, a quantitative study of the difference between traditionally reinforced and fibre reinforced concrete for the project-specific segment design.

About Mahmood Khwaja
An Associate at CDM Smith, Mahmood leads the tunnels/underground engineering practice at CDM Smith.  Mahmood is an accomplished geo-structural/tunnel engineer, project manager and technical leader with more than 30 years of experience in design of tunnels and underground structures, ground improvement, and support of excavation systems.  Mahmood has worked on national and international projects; holds a Bachelors and Masters degrees in Civil Engineering from University of Massachusetts; is registered is nine states.

Addressing Project Challenges and Integrating Construction Method Flexibility for the Rand Park Stormwater Diversion Tunnel, Keokuk, Iowa
Speaker: Mahmood Khwaja, CDM Smith, Waban, Massachusetts

At an average invert depth of 85 feet, the Rand Park stormwater diversion tunnel is 2,920 feet long and has a 10-foot internal diameter.  While the tunnel horizon is, primarily, within the regional Warsaw Shale, there are limited extent of mixed-face conditions in proximity of the junction structure at Fulton Street.  With an appreciable distribution of geodes, the Warsaw Shale is interbedded with limestone.  The project is on an accelerated design schedule and faces challenges, including: developing bid documents featuring flexibility on construction approach while maintaining control on project cost and schedule; addressing significant slope stability issues within the project limits; baselining complex subsurface conditions; and, meeting an anticipated short construction period.  The paper presents the detailed design and bid document development approach that focuses on these project challenges.

About Mahmood Khwaja
An Associate at CDM Smith, Mahmood leads the tunnels/underground engineering practice at CDM Smith.  Mahmood is an accomplished geo-structural/tunnel engineer, project manager and technical leader with more than 30 years of experience in design of tunnels and underground structures, ground improvement, and support of excavation systems.  Mahmood has worked on national and international projects; holds a Bachelors and Masters degrees in Civil Engineering from University of Massachusetts; is registered is nine states.

Hard Rock Tunnel Rehabilitation: A Smaller Demonstration Project Informs Design of Complete Tunnel Rehabilitation Project
Speaker: Kushwant Chohan, McMillen Jacobs Associates, San Francisco, CA

San Francisco Public Utility Commission is currently designing a $140 million rehabilitation and repair project for the Mountain Tunnel, scheduled to begin construction in 2020. A $5.9 million interim repair contract was undertaken in 2018/2019 to perform portions of work and provide a demonstration of the project elements. The interim repairs, performed during a 60-day tunnel shutdown, included repairs to sections of tunnel liner, contact grouting, invert smoothing/paving, and construction water treatment. This paper discusses lessons learned from the design and construction of the interim contract and how these elements will be implemented in the larger Mountain Tunnel Improvements Project

About Kush S. Chohan:
Kush S. Chohan, PE, GE is an Associate Engineer at McMillen Jacobs Associates in their San Francisco office. He has 14 years of hands-on civil and geotechnical engineering experience, providing design and construction support services on major infrastructure projects. His areas of expertise include geotechnical engineering, rock engineering, slope stability analysis, and tunnel and shaft excavation and support. Kush received his Bachelor of Science in Civil Engineering from CSU Chico and his Master of Science in Geotechnical Engineering from the University of Texas at Austin. He is a licensed Professional Engineer in California, Nevada, and New York and a licensed Geotechnical Engineer in California.

Everything is Deeper in Texas SAWS - Tunneling in the Navarro Claystone
Speaker: Daniel Maine, Brierley Associates, Austin, Texas

Aging infrastructure and increasing demand on sewer systems in San Antonio, TX is driving utilities to be bigger, deeper, and along more challenging alignments. Design for the replacement of a 54-inch sewer line through Lackland Air Force Base with a 104-inch sewer, via tunneling is underway. This 28,000-foot tunnel with eight shafts will be excavated through the challenging Navarro Formation Claystone. Challenges in designing this tunnel and how case histories of tunneling in this and similar formations helped develop the final design are discussed.

About Daniel Maine
Daniel Maine has a Masters Degree in Geotechnical Engineering from Virginia Tech. He has been involved in tunneling projects his entire career. He has worked in Virginia and central Texas and has been a Civil Engineer for a decade. He led the tunnel design efforts on the W6 Upper Segment project for Brierley Associates as a sub-consultant to Kimley-Horn. He enjoys woodworking and the outdoors in his spare time.

Behavior of Large Diameter Segmental Lining
Speaker: Mike Mooney, Colorado School of Mines, Golden, Colorado

Large diameter segmental lining systems are increasingly being planned for in highway and transit tunnels in North America (e.g., Seattle, LA, Virginia, Toronto, San Jose). Many behavioral and design assumptions from the more common 20-25 ft transit tunnels are applied to large diameter tunnels, however, with little supporting evidence. This paper addresses, through analysis and extensive review of full scale tests conducted globally, a number of critical aspects that are quite different for large diameter lining, including segment joint rotational stiffness, slenderness ratio, and whole ring behavior with 10-12 joints compared to the 5-6 of most liners to date.

About Mike Mooney
Mike is the Grewcock Chair Professor of Underground Construction & Tunneling at Colorado School of Mines. He serves as Director of the Center for Underground at Mines. Mike teaches courses and leads research in tunnel design and construction, support of excavations, and instrumentation/monitoring. Mike was Scientific Committee chair for WTC 2016 in San Francisco and serves on the executive board of UCA. Mike is a registered Professional Engineer is a consultant on tunneling projects..

Brushy Creek Regional Utility Authority Phase 2 Raw Water Delivery System Project
Speaker: James Parkes, Schnabel Engineering, Baltimore, Maryland

The Brushy Creek Regional Utility Authority (BCRUA) is a partnership of the cities of Cedar Park, Round Rock, and Leander, Texas. The Phase 2 Raw Water Delivery System is a new deep water intake and conveyance system at Lake Travis. The estimated $160M project includes two lake taps with multilevel screens; a 9,000 LF gravity intake tunnel with a minimum 8-ft internal finished diameter concrete liner; an underground suction chamber with 6 well shafts; a 30-ft diameter, 300-ft deep construction access shaft; a 2,600 LF transmission tunnel with an 84-inch welded steel final liner; an exit shaft approximately 155 feet deep at the end of the transmission tunnel; a 145 MGD pump station with 10 pumps; and a maintenance building for chemical feed systems to the intake shafts. The majority of the underground work will be in limestone of the Glen Rose formation. Final design is underway with anticipated bid date of June 2021 and construction start date of January 2022. Major project elements, design developments, constraints, procurement methods, and project schedule are presented herein.

About James Parkes
James Parkes is the Technical Tunneling Director with Schnabel Engineering’s Tunneling Services Group. He graduated summa cum laude with BS and MS degrees in civil engineering from Virginia Tech. He has 20 years of experience in the geotechnical and tunnel design for underground works and is licensed in 10 states. His experience includes tunnels, microtunnels, trenchless installations, and shafts in both soil and rock for water, wastewater, and transit facilities.

Highway Connection through Ouachita Mountains - Arkansas Tunnel Studies
Speaker: Eric Wang and Raymond Sandiford, HNTB Corporation, New York, New York

Bypassing and lessening traffic impact on very historic Hot Springs, the Arkansas State Highway and Transportation Department (AHTD) initiated a high-level tunnel feasibility study for proposed east – west arterial highway under Hot Springs National Park. Supporting AHTD’s due diligence comparison of open-cut versus tunnel option, study addressed feasibility, constructability, and conceptual cost and schedule estimates for new tunnel through elevated ridge terrain featuring very hard Arkansas Novaculite formation. Site survey and local geologic data informed development of practical sequential excavation method (SEM) tunneling approach to address sensitive environmental conditions. Tunnel envelope optimization efforts helped meet AHTD minimum operational and NFPA 502 safety requirements.

About Eric Wang
Eric is an Associate Vice President and East Operations Manager for HNTB's National Tunnel Practice with more than 30 years of experience. Past projects include MTACC's Number 7 Subway Line Extension, MTACC's East Side Access, NJ Transit's Trans-Hudson Express (THE) Tunnel, MTA Baltimore RedLine, Ohio River Bridges - East End Crossing Tunnel and DART D2. He is a licensed professional engineer in 6 states. Member of ASCE Geo-Institute's Underground Engineering & Construction Technical Committee.

About Raymond (Ray) Sandiford:
Raymond (Ray) Sandiford is the National Practice Lead for Geotechnical Engineering for HNTB. He has also been the Project Management Consultant to Amtrak for the B&P Tunnel replacement project. Ray has been involved in heavy construction for over 40 years. Prior to HNTB, Ray was the Chief Geotechnical Engineer for the Port Authority of New York and New Jersey and involved in all the major development work at all the agencies facilities. He is a licensed Professional Engineer in the states of New York, New Jersey and Maryland and he received his bachelor’s degree from SUNY Stony Brook and his master’s degrees from Columbia University. Ray is a member of SME and an Emiratis member of both the Moles and the ASCE.

Allegheny County Sanitary Authority - Tunnel System Preliminary Planning
Speaker: Mike Lichte, Allegheny County Sanitary Authority, Pittsburgh, Pennsylvania

ALCOSAN’s planned improvements to better manage wet weather responses include a network of storage tunnels, green infrastructure and WWTP expansion to meet a federal mandate. A Preliminary Planning (PP) Project began in 2017 to optimize the tunnel system and complete preliminary engineering studies. The PP project will be completed in November 2020 with final design anticipated to begin in 2021.  The tunnel system consists of approximately 15 miles of 14 to 16 ft diameter tunnels, approximately 20 drop shafts and 5 miles of near surface consolidation sewers. This paper will review preliminary planning and design aspects and anticipated construction sequencing.

About Mike Lichte:
Mike Lichte, has been in his current position as Manager of Planning in the Regional Conveyance Department at ALCOSAN since 2008. The Regional Conveyance Department oversees the day to day operation of approximately 90 miles of Interceptor Sewers and over 300 Regulator Structures.

Mike’s efforts include the current, on-going planning activities associated with the regional wet weather control plan. In addition, Mike oversees planning activities associated with the ACT 537 program and manages several interceptor repair and rehabilitation contracts. Mike has over 25 years of experience in water and wastewater projects. In his former position with the Pittsburgh Water and Sewer Authority, Mike was the Director of Engineering and Construction.

Mike received a Bachelor’s Degree in Aquatic Environments from Allegheny College in 1986 and a Master of Science in Civil Engineering from the University of Pittsburgh in 1992. Mike is a licensed professional Engineer in the State of Pennsylvania and a member of the American Society of Civil Engineers and the Water Environment Federation.

About Kim Kennedy:
Kim Kennedy, P.E., has served as ALCOSAN’s Director of Engineering and Construction since 2018. Kim received her Bachelor of Science Degree in Civil Engineering from Bradley University and her Masters of Science in Environmental Engineering from the University of Pittsburgh.  Before joining the Authority, Kim worked in the engineering consulting industry for twenty years. She is currently a board member of the Engineers Society of Western Pennsylvania (ESWP), and also serves as board secretary for the Pittsburgh chapter of the Society of Women Environmental Professionals.

Determining the Feasibility of Tunneling for Flood Mitigation after Hurricane Harvey
Speaker: Brian Gettinger, Freese and Nichols, Houston, Texas

Up to 60 inches of rain fell during Hurricane Harvey leading to widespread flooding, $125 billion in damages and 65 deaths. Existing flood mitigation infrastructure is struggling to handle increasingly frequent large storms events and increasing population. Large diameter, deep inverted siphon tunnels have been proposed as a solution to improve system conveyance capacity; however, few large diameter tunnels have been built in Houston due to perceived challenges with soft clay and sandy soils, high groundwater, and faulting.

This paper discusses the outcome of a feasibility study including insights on geotechnical conditions, applicability of tunneling, conceptual cost estimate, and hydraulic capacity for the potential very large diameter and long inverted siphon tunnel(s).

About Brian Gettinger
Mr. Gettinger is the Tunneling Services Leader for Freese and Nichols. Brian Gettinger has been involved in the planning, design, and construction of tunnels and other heavy civil infrastructure in Texas and across the United States. He is a graduate of the University of Missouri – Kansas City with a degree in Civil Engineering and an MBA. His experience includes design, cost estimating, inspection and construction management of tunnels and grouting of shafts and reservoirs.

Estimating Project Contingency Reserves – Now What?
Speaker: Keith Ward, City of Seattle Public Utilities, Seattle, WA and Connor Langford, Mott MacDonald, Vancouver, Canada

In underground construction risk and uncertainty is prevalent from the very outset of a project.  A risk and uncertainty analysis is useful to help convey confidence in delivering a project within an available budget.  But once the analysis is performed, what should a Project Owner do with the information and data available and how does it shape the outcome or even viability of a project?  This paper looks back at projects from a “what, if anything, could have been done better” and looks forward as to “how should the analysis inform delivery methods and contingency reserves once bids are received”.

About Keith Ward:
Keith Ward, PMP, PE has more than 28 years of project-delivery and organizational leadership experience in the private and public sectors as an engineer, construction manager, project manager, and program director. Keith is currently the Project Executive of the Ship Canal Water Quality Project where he leads a team of over 350 staff and consultants who are designing and constructing the largest project in the history of his organization. He has a strong interest in successful teamwork, cost estimating, and risk management. In his free time, Keith enjoys alpine climbing in the surrounding mountains throughout the summer months and skiing in the winter months.

About Connor Langford:
Following graduation from Geological Engineering at Queen's University in 2008, Connor worked as an engineer-in-training for Hatch and Hatch Mott MacDonald (HMM). His major projects included commissioning of critical mine systems at the Nickel Rim South Mine and the preliminary design for NWMO’s deep geologic repository for low and intermediate nuclear waste. In 2010, he went back to complete a Ph.D. in geological engineering with a focus on understanding uncertainty and risk in the design of underground structures.

After finishing his Ph.D. in 2013, He relocated to Vancouver to work for Mott MacDonald in the Tunnels Group. Since then he has worked on a number of tunnel projects across North America as a project manager, design coordinator, project engineer and risk management.

Progressive Design Build in Silicon Valley
Speaker: Nik Sokol, Arup, Oakland, California

The Silicon Valley Clean Water Gravity Pipeline (SVCW) is among the first tunnel projects to be procured using Progressive Design Build (PDB). Selected to provide cost certainty after the 60% design level and to allow greater coordination of the design with operations and maintenance, PDB also facilitates collaborative working between owner, contractor and designer. The flexibility of PDB procurement has allowed early milestones to be achieved during Stage 1, prior the Stage 2 contract, including ordering the TBM and 100% design of the precast concrete segmental lining and TBM launch shaft. Successes and challenges of the PDB process are discussed.

About Nik Sokol
Nik Sokol is a Certified Engineering Geologist and an Associate in Arup’s global Tunnel Design team. He has over 20 years of underground design and construction experience gained working on infrastructure projects on 5 continents, in a broad range of ground types, and using a variety of excavation and ground support methods.

Recent Experience with Bond Market Investors on P3 Projects with Large Tunnels
Speaker: David Mast, AECOM, Cleveland, Ohio

The Michigan Department of Transportation (MDOT) I-75 Modernization Project (Segment 3) in Detroit and Oakland County will be accomplished under a 30-year Private-Public Partnership (P3) with a contract value of over US$1 billion. Oakland Corridor Partners (OCP) was awarded the 30-year P3 Design-Build-Finance-Maintain project. In addition to highway road and bridge replacements, OCP will construct a nearly 4-mile long, 14.5-foot ID storage tunnel to eliminate pump stations and reduce road flooding. OCP assisted MDOT with securing financing, including bond ratings. The paper will share unique experience of winning and financing a P3 project with a large tunnel component.

Owner Flexibility and Contractor Experience Lead to Project Success
Speaker: David Mast, AECOM, Cleveland, Ohio

The Dugway South Relief and Consolidation Sewer was substantially completed in September 2018 for the Northeast Ohio Regional Sewer District.  McNally Tunneling Corporation utilized a variety of tunneling and construction methods to accomplish this critical CSO control measure system. They utilized bid document flexibility to choose efficient construction methods, including use of a single TBM for soft ground and shale rock mining. McNally proposed several improvements based on the capabilities of their equipment and their own experience. This paper will discuss the challenges, solutions, and effectiveness of the design and construction methods utilized to complete the project.

About Dave Mast
Dave Mast is a Senior Project Manager and Practice Leader for the AECOM North America Tunnel and Underground Center of Excellence. He is a graduate of Purdue University of West Lafayette, Indiana. He has been an Underground Engineer and Project Manager for over 20 years, with primary concentration in sewer and stormwater tunnel planning, design, and construction. He is based in AECOM's office in Cleveland, Ohio.

Reaching New Depths: Innovations in Technological Site Characterization Tools for Integrated Tunnel Design
Speaker: Erin Sibley, Mott MacDonald, Chicago, Illinois

Traditional methods for capturing and analyzing site characterization data for tunnel projects, such as hand-written field logs and CAD-based subsurface profiles, have remained relatively disconnected from the overall ground model and tunnel structural design. However, recent innovations in digital automation and data collection offer the opportunity for more holistic design, allowing detailed information to be carried through the exploration stage to subsequent project phases. This paper presents state-of-the-art tools for design development, such as a cloud-based field report application, digital data planning and management tools, and 3D geologic modeling software, and how they are utilized for seamless, integrated tunnel design.

About Erin Sibley
Erin Sibley received her Ph.D. in geotechnical engineering before joining Mott MacDonald in Chicago as a Tunnel Engineer. With extensive practical knowledge of geotechnical testing and instrumentation, her experience includes subsurface exploration, site characterization and modeling, as well as geo-structural analysis and design. Dr. Sibley’s expertise is also in liquefaction assessment, seismic hazard analysis, and earthquake engineering.

Jacked Pre-Cast Segmental Shaft Construction Methodologies
Speaker: Joe Anderson, Golder, Saskatoon, Saskatchewan

New market adoption of jacked pre-cast segmental shaft construction methodologies. An overview of the jacked segmental methodology and its’ application to varying ground conditions; the ability to deliver water-tight, rationalized structures through soft rock, non-cohesive and cohesive ground. Paired with under-pinned, under-reamed and corbeled segments, sprayed concrete linings and concreting under-water, this is a safe, versatile, quick construction methodology that can be designed for near surface infrastructure up to 70m deep.

Pre-cast segmental methodology can also minimize the need for wet process applications on site and assist in reducing site waste streams due to its predominantly pre-cast system components.

About Joe Anderson, P.E.
 Joe is a structural/tunnel engineer at Golder, based in Saskatoon, Canada.

 Joe has 10 years’ experience across the mining and tunneling industries  and has been involved in the design and construction of multiple shafts  and tunnel projects in both competent and unstable ground utilizing across  the United Kingdom and North America using NATM/SEM techniques and steel, cast iron and composite lining systems.

TBM Hardening and Anti-wear Mechanisms Against Ground Abrasion
Speaker: Donald Del Nero, Hatch, Clarkesville, Georgia

Soil and rock abrasion can have substantial impacts on TBM productivity and downtime events. The impacts of abrasion must be considered holistically for all TBM types and their individual components; from cutters to the muck scoops, from the plenum to the screw, and from the slurry pumps to the slurry plant. Productivity and downtime events from abrasion often point to metallurgical deficiencies. The paper will therefore highlight metallurgical aspects of abrasion resistance, common TBM wear patterns, customized anti-wear hardening mechanisms, custom steel alloys on the market and on what projects they have been implemented.

About Don Del Nero
Don Del Nerois the Tunnel Director for the United States with Hatch. He holds a minor in geology, BS in Civil Engineering, MS in Geotechnical Engineering, and has 31 years of underground experience. He is also an instructor for the NASTT New Installation Course, Breakthroughs in Tunneling, Microtunneling, and Risk Management in Underground Construction Short-courses and was the Program Chair for the 2018 No-Dig Show.

Union Square Market Street Station
Speaker: David Abrahams, WSP, NEW YORK, New York

The Union Square Market Street Station was constructed using top-down, cut and cover excavation methods utilizing 150 foot battered drilled shafts as permanent ground support, rendering it one of the most unique subway station configurations in the world. San Francisco’s Central Subway Project is a 1.7-mile-long subway extension with three underground stations.  Its temporary and permanent ground support, compensation grouting activities, excavation dewatering, and existing conditions will be presented. Entrances at the historic Union Square and a second entrance that integrates with an existing BART station will also be described.

About David Abrahams
David Abrahams is a supervising engineer focusing on the design and management of large underground projects.  He has played various roles in a variety of project delivery methods.   He has worked on projects in all phases of development, from preliminary engineering, through detailed design and into construction. He has a diverse experience in the design of underground structures in soft ground and rock, including bored tunnels, caverns, cut-and-cover and shafts.

About Kenneth Johnson:
Ken has nearly 40 years of experience in earth science and geological engineering, having worked on issues involving tunnels, deep excavations, hydrogeology, excavation dewatering, landslides and debris flows, on a variety of different projects throughout the San Francisco Bay Area, California, the United States and internationally.  Specific Bay Area projects where he has had a lead role include: the design and construction of the Central Subway in San Francisco, California High Speed Rail program, BART to Silicon Valley Phase II, The BART Berkeley Hills Tunnel, and construction dewatering sites around the region.

EPBM Pro-Active Tracking and Progressive Optimization
Speaker: Colin Lavassar, McMillen Jacobs, Washington, D.C.

Current Earth Pressure Balance TBMs (EPBM) are equipped with a multitude of sensors that continuously record operational data. These data feeds can produce an almost overwhelming amount of information, especially when combined with results of geotechnical instrumentation programs that monitor soil and groundwater response to tunneling. Owners, designers and contractors benefit from pro-active analyses and visualization of these data sets though as this enables operational changes to be made in a timely manner to optimize TBM performance. Furthermore, a progressive response is often necessary to efficiently overcome problems that result from a combination of root causes, especially during TBM launch and the infamous “Learning Curve”.  This paper focuses on the lessons learned regarding TBM data analysis and visualization during construction of the Anacostia River Tunnel and how these have been applied to the North East Boundary Tunnel, in Washington DC.

About Colin Lavassar:
Mr. Lavassar is a geotechnical engineer with McMillen Jacobs Associates. He has 12 years of experience in the heavy civil industry working on major underground projects for light rail and CSO control systems. Since 2016, Mr. Lavassar has been working in Washington DC for DC Water’s Clean Rivers program. The Clean River’s program includes 5 major tunnel contracts that will capture combined sewer overflows to the Potomac and Anacostia Rivers, improve water quality and reduce the likelihood of inland flooding in parts of the capital. Mr. Lavassar’s presentation today will discuss lessons learned from the Anacostia River Tunnel project and how these have been applied to subsequent construction efforts that make up the DC Clean River’s program.

Small Diameter Tunnelling: Limitations and Machine Concepts
Speaker: Peter Schmaeh, Herrenknecht AG, Schwanau-Allmannsweier,

Small diameter tunnels are considered for a large variety of applications from water and gravity tunnels for sewage to tunnels for cable and telecommunication lines. Furthermore, challenging crossings of water and traffic ways represent an increasing niche market for small TBMs, including pipeline installations. Especially in the pipeline industry, the tunnel diameter is not defined by the application itself but by the applicable tunnelling method. This creates a demand for small tunnels, even on long distances and difficult ground conditions.

Safety aspects in mechanized tunnelling are becoming increasingly important. Latest safety regulations have tightened requirements regarding machine diameter and accessibility with considerable impact on personal access and logistics. As a result, larger diameters will come more into focus or unmanned procedures like pipe jacking will take over a share of the smaller diameters of up to four meters.

About Peter Schmäh
Peter Schmäh was born in 1968 in Constance, Germany. After his degree in Mechanical Engineering at RWTH Aachen, he started working for Herrenknecht AG in 1998 as a Project Manager, in charge of worldwide Utility Tunneling projects. In 2011, he has become Member of the Executive Board of the Business Unit Utility Tunnelling. In this position he is responsible for sales of tunnelling and shaft sinking equipment, product management and the rental department.

Deep Shaft Sinking Through Limestone, Mudstone, and Halite
Speaker: Seth Pollak, Arup, New York, New York

The Jansen Project is a new potash mine development being undertaken by BHP in Saskatchewan, Canada. The project consists of a pair of shafts which have been sunk to a depth of approximately 1 km. Unlike previous shafts within the province, Jansen was sunk using new technology in the form of Herrenknect’s Shaft Boring Roadheader (SBR) machine. The shaft liner is being constructed via a two-pass method; with the final liner to be constructed from the bottom up. Shaft stability in the sinking condition is ensured through a combination of artificial ground freezing and primary ground support. The focus of this paper is the area of the shaft at a depth of 700 m to 900m composed of limestone, mudstone, and halite. This paper covers the characterization, primary ground support design and construction observations made within these zones.

About Seth Pollak
Seth Pollak is an Associate in Arup’s New York office with 14 years of experience in hard rock and soft ground tunneling. He has designed concrete and cast iron tubbing shaft linings for two of the three Shaft Boring Roadheader mined projects worldwide. Seth holds a Master’s degree in Mining and Earth Systems Engineering from the Colorado School of Mines and is both a registered Professional Engineer and Geologist.

The Northeast Corridor Superconducting Maglev Project
Speaker: Cosema E. (Connie) Crawford, Senior Vice President Rail/Transit Global Practice Leader, WSP USA, and Vojtech Gall, Ph.D., P.E., Principal, Gall Zeidler Consultants

The Northeast Corridor Superconducting Maglev Project (SCMAGLEV) entails the construction of a high-speed train system between Washington, D.C. and New York City, with the first leg between Washington and Baltimore, MD. The system operates using an electromagnetic levitation system developed and deployed in Japan that achieves an operating speed of 500 km/h. SCMAGLEV is an innovative project that will shorten travel times between Washington D.C. and Baltimore to 15 minutes, and connect to New York City in under an hour. In 2019, the design is being advanced to an engineering level sufficient to support an Environmental Impact Statement. A preliminary geotechnical investigation campaign was also underway. This presentation provides an update on the project and discusses construction of the predominantly soft ground TBM driven tunnels.

About Cosema E. (Connie) Crawford:
Connie Crawford has over 35 years of public and private sector experience in the management, design and construction of major transportation programs. She served as Chief Engineer for MTA New York City Transit, where she was responsible for a $2.25 billion annual capital program for subway and bus infrastructure. Previously, as Chief Engineer for the New York City Department of Transportation, she managed planning, design, construction and maintenance of the City’s bridges and tunnels. Ms. Crawford serves as the chief engineer for the Northeast Corridor Maglev Train project that proposes to provide one hour service at 311mph between New York City and Washington, DC. She managed major transit projects in the Middle East, including project director for over $2 billion of construction on the Doha Metro system, and project coordinator for a 100km metro system in Madinah, Saudi Arabia. She currently oversees the Santa Ana Streetcar Project in California for the Federal Transit Administration. Ms. Crawford holds a master's and bachelor's degree in engineering from Princeton University, where she also taught a course on bridge engineering. She is a licensed professional engineer and is involved in numerous professional organizations, including the Transportation Diversity Council, FIRST Robotics and the Moles.

About Vojtech Gall, Ph.D., P.E.
Dr. Gall has over thirty years of experience in the design, construction, and construction management of tunnels and underground structures. His expertise encompasses soft-ground, mixed-face, and rock-tunneling utilizing TBM, conventional tunneling (SEM/NATM), and cut-and-cover techniques.

He frequently serves on expert review panels dedicated to the investigation and improvement of tunneling schemes ranging from initial inception stages through final design development at bid document level. His peer review services relate to a wide variety of facilities ranging from hydro-power schemes in remote settings to complex transit structures in urban settings.

He is a Principal of Gall Zeidler Consultants, a firm specializing in geotechnics, tunnel engineering and tunnel consulting. He has authored over 50 technical publications on the subject of tunneling and lectured extensively on the implementation of modern tunneling techniques.

Friday Tunnel Demand Plenary Session (Live)
The Tunnel Demand Forecast session will have presentations from various owners and engineers regarding upcoming projects throughout the US and Canada. An overall update and summary of North American tunnel projects will also be given. Some of the projects and programs to be discussed will include:

• MWRA Metropolitan Tunnel Program, Boston, Mass.
• DART D2 Subway, Dallas, Texas
• Sound Transit, Seattle, Washington
• Superconducting MAGLEV Project, Baltimore/Washington D.C.
• Canadian Upcoming Projects Update

Each presentation will last approx. 20 minutes with limited question and answer period to follow. Presentation list is subject to change based
Panelists: Jonathan Klug, David R. Klug & Associates, Inc.

• Matt Preedy, Sound Transit
• Brandi Crawford, HNTB
• Mala Ciancia, HNTB
• Sanja Zlatanic, HNTB
• Kathy Murtagh, Massachusetts Water Resources Authority
• Fred Brandon, Massachusetts Water Resources Authority
• Gary Kramer, Hatch, Massachusetts Water Resources Authority
• Dominic Reda, Gall Zeidler Consultants