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Wednesday | Design Track Sessions

 

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 -11:30 am     Sessions

11:30 am - Noon        Break

Noon - 1:00 pm        Live Q&A ¬†| Wednesday Speakers

2:00 pm - 3:00 pm    Live Q&A | Tuesday Speakers


On-demand Sessions

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.

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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.

The Santa Clara Valley Transportation Authority (VTA) is currently planning Phase 2 of the extension of the Bay Area Rapid Transit (BART) system into Silicon Valley, through downtown San Jose, California. The 6-mile-long extension will include a 5-mile long tunnel below downtown San Jose and will include 3 underground stations and one at-grade station. This presentation will include an update on the current status of the project and a look ahead.

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.

 

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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.

 

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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.

 

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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.

 

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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.

 

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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.

 

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Live Q&A Session - Noon

Join the speakers from today’s on-demand 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 noon MDT.

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Live Q&A Session - Tuesday Session Speakers | 2 pm MDT

Join the speakers from Tuesday's on-demand 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 2 pm MDT.

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