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Monday | Taste of NATWeek + Owners’ Forum


Welcome to NATWeek: A Virtual Experience!
You can begin to access today’s on-demand content at 9 am MT. Be sure to join the Live Q&A to hear from the presenters and pose your industry questions to the experts.

Today's Schedule

9:00 am          Taste of NATWeek

11:00 am       Live Q&A

12:30 pm        Owners’ Forum

On-demand Sessions

Monday Sessions Sponsored by DSI Underground


Innovative SOE Solutions for Shaft Construction: Getting to Depth With Diaphragm Walls at Westerly Storage Tunnel Info 
Speaker: Jewels Stover, Nicholson Construction, Canonsburg, Pennsylvania

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.


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The Three Rivers Protection & Overflow Reduction Tunnel (3RPORT) – Design Challenges of the Launching of Pressurized Slurry TBM Info 
Speakers: Roberto Schürch, 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 Schürch

Dr. R. Schürch 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.

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Design–Build Procurement of the Hampton Roads Bridge–Tunnel Expansion Info 
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.


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Multiple use of TBMs for Singapore’s ground breaking conveyance system of Deep Tunnel Sewerage System Phase 2 Info 
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.


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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.

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Live Q&A Session
Join the speakers from today’s sessions. This is your chance to ask questions from industry experts and learn from their collective answers and conversation. This dynamic live session will begin at 11 am MDT.

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

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