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Technical Sessions that Enlighten

The NAT Conference is proud to present technical sessions hosted by some of the leading innovators and technology from around the world.
Check back regularly for the latest details.

Updated 5/22/2024

Sessions-At-A-Glance

Case Histories: SEM/NATM Excavation Techniques
Design: Numerical Modeling
Planning: Project Design
Technology: TBM Technology
Case Histories: Shaft Excavation, Tunnel Rehabilitation & Challenges
Design: Tunnel Lining Design
Planning: Rehabilitation, Fire, Safety & Training
Technology: Digital Technology
Case Histories: Geotechnical and Contracting Cases
Design: Challenging Design Issues 

Planning: Underground Project Delivery
Technology: Construction Innovation
Case Histories: TBM Performances and Challenges I
Design: Innovative Designs
Planning: Underground Project Risk
Technology: Innovative Solutions
Case Histories: TBM Performances and Challenges II
Design: Design of Underground Spaces
Planning: Underground Construction and Challenges
Technology: Design Innovations

Monday, June 24 | Opening Plenary

8:30 am – 10:00 am

Opening Plenary – UCA Awards Session

Kick off NAT by celebrating industry excellence. The opening plenary recognizes the recipients of the 2024 UCA Awards. Don’t miss this uplifting multimedia presentation. UCA honors the following remarkable 2024 Award Winners:

 

UCA Lifetime Achievement Award

Gary A. Almeraris, Skanska
Randall J. Essex, Mott MacDonald
W. D. “Toby” Wightman, Retired

UCA Muddy Boots Award

Sean Sladicka, Kiewit Corp.

UCA Outstanding Educator

Mike A. Mooney, Colorado School of Mines

UCA Project of the Year Greater than $500M

Lane Construction Corporation
Northeast Boundary Tunnel

 

UCA Person of the Year

Robert J. F. Goodfellow, Aldea Services Inc.

UCA Young Member Award

Rajat Gangrade, Arup

UCA Project of the Year $50M to $500M

Guy F. Atkinson Construction LLC
HJAIA Plane Train Tunnel West Extension Project

Monday, June 24 | Morning Sessions

10:00 am – 11:45 am

Case Histories: SEM/NATM Excavation Techniques

Presidential C

Chairs: Dave Dorfman; Walsh Group, Warwick, NY
Mark Claassen; Arcadis, Toronto, ON

 

10:00 am

Introductions

 

10:05 am

Construction Phase Services for Australian and North American SEM Tunneling

Yun Bai; Delve Underground, Sydney, New South Wales, Australia
Michael Salcher; Gamuda Australia, Sydney, New South Wales, Australia
Sarah Wilson; Delve Underground, San Francisco, California, United States
Mark Trim; Delve Underground, Sydney, New South Wales, Australia

Over the last decade more than 62 miles (100 km) of civil transport tunnels were constructed in Sydney, Australia, using the sequential excavation method (SEM). The WestConnex motorway tunnels, each stage of which used over 20 road-headers to excavate up to 40 tunnel headings, had numerous caverns up to 100 feet (30 m) wide and 82 feet (25 m) high. SEM tunnels in North America typically have far fewer active headings. This paper examines the differences in scope and risk allocation for construction phase services, including comparison of the Permit to Tunnel (PTT) process in Australia and the Required Excavation and Support process in North America.

 

10:25 am

Influence of Early Ring Closure of Center Drift on Main Tunnel Excavation under High Overburden Ground

Devini Abeyawardena; Penta-Ocean Construction Co., Ltd, Tokyo, Tokyo, Japan
Simin Zhai; Penta-Ocean Construction Co., Ltd, Tokyo, Tokyo, Japan
Sadatoshi Ohmori; Penta-Ocean Construction Co., Ltd, Tokyo, Tokyo, Japan
Nobuharu Isago; Tokyo Metropolitan University, Tokyo, Tokyo, Japan

A road tunnel is planned to be constructed in soft, high overburden ground of around 600m in Japan by using the center drift advancing method. The dodging effect and early ring closure of the center drift were expected to reduce the displacement and deformation of tunnel and promote safe construction. The measurement result during construction was analyzed and those effects, which the displacement and deformation after the widening excavation decreased and its effect increased as the center drift radius increased, were confirmed by numerical analysis. Also, the effect of the early closure of center drift after widening excavation did not have much effect.

 

10:45 am

Chimney Hollow Reservoir Project Inlet / Outlet Tunnel Excavation and Valve Chamber Construction

Kyle Kittle; Stantec, Louisville, Kentucky, United States
Gregory Raines; Stantec, San Diego, California, United States
Albert Ruiz; Stantec, Chandler, Arizona, United States
Kyle Knaeble; Barnard Construction Company Inc., Bozeman, Montana, United States
Ryan Gewargis; Stantec, Denver, Colorado, United States

The Chimney Hollow Reservoir Project (CHRP) is located southwest of Loveland, Colorado. CHRP is a component of the Windy Gap Firming Project, operated by the Municipal Subdistrict of the Northern Colorado Water Conservancy District. The inlet/outlet tunnel (IOT) for CHRP contains a reinforced concrete lined valve chamber with PVC membrane waterproofing that was excavated via sequential excavation method to a diameter of 30 feet. The IOT was excavated using both drill and blast and road header with ground support consisting of steel sets, rock bolts, wire mesh and shotcrete. The IOT will withstand 300 feet of water head and rock fill surcharge load from the dam embankment constructed over the tunnel.

 

11:05 am

Mitchell Point Tunnel, Oregon – Design and Construction

Matthew Fowler; WSP USA, San Francisco, California, United States
John Horne; WSP USA, Portland, Oregon, United States
Cole Bales; Anchor QEA, Seattle, Washington, United States
Taeyong Lee; FHWA, Vancouver, Washington, United States

Mitchell Point Tunnel near Hood River, Oregon is one of the more unique segments of the Historic Columbia River Highway and State Trail being constructed through the Columbia River Gorge. This 650-foot bike/pedestrian tunnel set to open in 2024 is being delivered by FHWA in partnership with Oregon DOT, Oregon State Parks, and the U.S. Forest Service. Primarily driven using drill & blast excavation methods through basalt, the shotcrete and dowel-supported tunnel features masonry portals and five “window adits” that provide illumination and views of the river similar to the original highway “tunnel of many vistas” built in 1915 that was removed in 1966 to make way for Interstate 84. This paper summarizes the planning, design, and construction.

 

11:25 am

The Upper Hidden Basin Diversion Project Design and Construction at Terror Lake – Kodiak, Alaska

Steve Brandon; Schnabel Engineering, Sterling, Virginia, United States
Julius Strid; Schnabel Engineering, Seattle, Washington, United States,
Jennifer King; Kodiak Electric Association, Inc., Kodiak, Alaska, United States

The Upper Hidden Basin Diversion (UHBD) tunnel was driven approximately 1.2 miles by the drill-and-blast method primarily through massive granite bedrock geology for the Kodiak Electric Association, Inc. (KEA) in Kodiak, Alaska. The tunnel was driven from both portals with a constant 11-ft straight-leg horseshoe cross-section. The design and construction of the tunnel was driven by logistics and weather conditions due to its remote location and the rugged terrain of the project setting. This paper will discuss the successful completion of a challenging project over a five-year period from preliminary planning through the design and construction phases.

 

11:45 am

Application of the Observational Method in the T-48 Tunnel Project in the Himalayas

Anuradha Khetwal; WSP USA, Highlands Ranch, Colorado, United States
Sandeep Khetwal; Black & Veatch, Highlands Ranch, Colorado, United States
Andrea Panciera; Lombardi Engineering Limited, Bellinzona, Bellinzona, Switzerland

The observation method is a design optimization approach for the drill and blast method in tunneling. This method includes first identifying the hazard scenarios through site investigation, formulating suit-able solutions, obtaining feedback during construction, and finally using that data to optimize the design methods. This paper illustrates the application of the observational method for T-48, a railway tunnel project in the Himalayas. It is a 10.2 km long tunnel with a parallel escape tunnel and 26 cross passages. The use of observational methods in this project optimized the overall tunnel design and considerably saved the overall project cost.

 

 

 


Design: Numerical Modeling

Presidential A

Chairs: Eleanor Sillerico; Mott MacDonald, Los Angeles, CA
Matthew Over; JCK Underground, Hendersonville, TN

Sponsored by: 

 

10:00 am

Introductions

 

10:05 am

The Application of Load Combinations in Ground-Structure Interaction Software

Dale Brunton; Arup, Toronto, Ontario, Canada
Michael Dutton; Arup, Toronto, Ontario, Canada
Robert Adams; Arup, Toronto, Ontario, Canada

Tunnels and other underground structures are typically designed using ground-structure interaction models instead of traditional structural analysis programs. This allows for the degree of load sharing between the two bodies to be calculated, allowing for a more efficient design. While modern codes outline the use of limit states with factors on applied actions, limit states are not typically compatible with ground-structure interaction models. Consequently, the engineer is left to develop rational methods for incorporating load factors into their analyses. Several methods can be considered, including the Largest Factor Method, Averaging Method, Subtraction Method, and Split Factor Method. This paper discusses the approaches, compares their effects using a case example, and provides a recommendation for designers.

 

10:25 am

Numerical Impact Assessment of Axially Loaded Piles and Their Seismic Effects on an Existing Bored Subway Tunnel

Maziar Pasdarpour; GHD, Toronto, Ontario, Canada
Keivan PakIman; GHD, Toronto, Ontario, Canada

Transportation tunnels are highly sensitive to ground movements and are required to be stable and secure for safe operation. In urban areas, the interaction between tunnels and adjacent piles, which are widely used to support buildings and other structures, requires careful consideration. The seismic response of tunnels may vary depending on the lateral stiffness and strength of the tunnel walls, while the axial loading and seismic impact of adjacent piles may cause soil displacement and stress changes that can damage the tunnel lining. As a result, tunnel owners often impose strict limits on the design of new piles lying close to existing tunnels including maximum allowable tunnel deformation, stress change limits, and minimum tunnel to pile separation distances. This paper describes a numerical analysis of the influence of the axial loading and seismic impact of bored pile foundations on subway tunnels, undertaken using the finite element software Plaxis 3D. Based on the results of the numerical analysis, the paper suggests a more realistic and less conservative approach for designing piles in close proximity to transportation tunnels.

 

10:45 am

ATSSE: Design Workflow for Construction Impact Assessment from EPB TBM-Induced Ground Movements

Roham Akbarian; Arup, Toronto, Ontario, Canada
Aidan Hopkins; Arup, Toronto, Ontario, Canada

Strabag, with Arup, is designing and constructing the ATSSE in Toronto, Canada. The 7.8 km long extension of the existing TTC Line 2 is in an urban area passing below existing structures, including Hwy401, the TTC Line 3 and thousands of utilities. Understanding construction impacts are an integral part of tunnel design. This paper proposes a design approach for assessing the impact to assets, providing a workflow linking “face pressure” and “volume loss” using numerical modelling. The step-by-step workflow is proposed for initial and detailed assessments on ground movements. The paper discusses the application of the workflow for ATSSE.

 

11:05 am

Design of Special Precast Lining Rings for Cross Passage Openings Using Finite Element Analysis and Shell Spring Models

Mehdi Ghasemi; GHD, Dartmouth, Nova Scotia, Canada
Alireza Ramezani; GHD, Markham, Ontario, Canada
Keivan Pak Iman; GHD, Markham, Ontario, Canada

The complex nature of seismic soil-structure interaction in pre-cast concrete tunnel linings (PCTL) around cross passages (CPs) requires the use of numerical methods of calculation. Local restraints on the PCTL from the CP collar cause differential movement and generate stress concentration in the PCTL rings adjacent to the CP opening. The radial and circumferential joints in the PCTL make it impossible to use simple closed-form solutions. In this paper, a 3D model of the tunnel (including eight adjacent fully closed rings and two cut rings at the CP opening) are created by SAP2000, with the surrounding geologic medium represented by soil springs. The two cut rings at the opening, and the two rings adjacent to the opening are specially reinforced with reinforcing steel while the remaining rings are steel fibre reinforced concrete (SFRC). A non-linear link has also been added to the model for both radial and circumferential joints consideration. Ground strains caused by seismic waves were then applied to the model accounting for the interaction between the tunnel structure and the surrounding ground. A series of 3D shell spring models were created to investigate the effect of ground springs, joint properties, and CP stiffness on the seismic behavior of the structure. Finally, the PCTL segment and all connectors were designed and checked for the most critical combinations of induced hoop force, bending moment, and shear force.

 

 

 


Planning: Project Design

Presidential B

Chairs: Shawna Von Stockhausen; Mott MacDonald, San Jose, CA
Amanda Foote; AECOM, Newburgh, IN

Sponsored by: 

 

 

10:00 am

Introductions

 

10:05 am

Risk-Based Ventilation Design for a Long Bidirectional Road Tunnel

Soroush Dabiri; ILF Consulting Engineers, Rum/Innsbruck, Tirol, Austria
Juan Carlos de Rueda; ILF Consulting Engineers, Rum/Innsbruck, Tirol, Austria
Reinhard Gertl; ILF Consulting Engineers, Rum/Innsbruck, Tirol, Austria

The Tunnel of Guillermo Gaviria Echeverri, spanning 6.05 miles, will be Latin America’s longest road tunnel, is currently under construction in Colombia’s Antioquia Department with a single bidirectional tube connected to a parallel rescue tube through multiple cross-passages. The study faces challenges in implementing the prescriptive semitransversal ventilation system due to design restrictions. Different ventilation concepts are explored to find the most suitable system for regular operation and fire scenarios. A quantitative risk assessment evaluates each alternative system and identifies the longitudinal ventilation system, accompanied by risk mitigation measures, as the safest choice, since it surpasses the prescribed semitransversal ventilation concept.

 

10:25 am

Design and Construction Challenges at the Piney Branch CSO 049 Storage Tunnel in Washington, DC

Ritika Kundu; Delve Underground, Bristow, Virginia, United States
Moussa Wone; District of Columbia Water and Sewer Authority, Washington, DC, District of Columbia, United States
Amanda M Morgan; Delve Underground, Washington DC, District of Columbia, United States
Tatiana K Proctor; Greeley and Hansen, Washington DC, District of Columbia, United States

The Piney Branch CSO 049 Storage Tunnel (PBST) will be the last major project for the DC Clean Rivers Program. The project includes construction of a 2,200-foot-long, 18-foot-internal-diameter storage tunnel; two connections to combined sewer infrastructure; and two shafts. Major challenges include excavation underneath an existing live outfall that must remain in service; excavation of the tunnel through several areas of low rock cover and mixed-face conditions; and negotiations with a variety of federal, regional, and local stakeholders to address project impacts. This paper describes the overall project scope; geotechnical conditions along the alignment; design and construction challenges; and construction procurement.

 

10:45 am

Microtunnel Shaft Construction in Louisiana

Lance Heyer; Lithos Engineering, Fort Collins, Colorado, United States
James Carroll; Lithos Engineering, Fort Collins, Colorado, United States

This paper describes the shaft design and construction for a 72-inch microtunnel under 14 active railroad tracks in Avondale, Louisiana. Initial shaft design for a deeper tunnel alignment considered secant piles with a jet grout plug. Final design for a shallower tunnel alignment included contractor input with support consisting of braced sheet piles with a jet grout plug. The authors further elaborate on jet grout implementation in very soft organic clay soils and the practical limitations of jet grouting. This paper emphasizes how all project participants worked together to utilize value engineering and alternative delivery on a unique tunneling project with a focus on temporary shaft support.

 

11:05 am

Shaft Design and Construction at the Hampton Roads Bridge-Tunnel

Pa Ousman Njie; WSP USA, Norfolk, Virginia, United States
Richard Giffen; Mott Macdonald, Norfolk, Virginia, United States
Luca Pellegrini; Hampton Roads Connector Partners, Norfolk, Virginia, United States
Martha Gross; Virginia Department of Transportation, Norfolk, Virginia, United States

The Hampton Roads Bridge-Tunnel (HRBT) Expansion project in Virginia includes parallel 1.5-mile (2.4 km) tunnels constructed using a tunnel boring machine (TBM). The TBM launching and receiving shafts were excavated within the footprint of two reclaimed islands abutting the navigation channel for the Port of Virginia. The shaft excavations – a circular tri-cell shaft at South Island, and a circular-rectangular twin-cell shaft at North Island – were supported by slurry walls up to 190 feet (58 meters) below the island surfaces. This paper describes specific design considerations for these shafts, as well as construction and quality-oversight aspects of their excavation and construction.

 

 

 


Technology: TBM Technology

Presidential Chamber A

Chairs: Max Engen; JF Shea, Greenwood, IN
Jeff Pargas; Delve Underground, New York, NY

 

10:00 am

Introductions

 

10:05 am

TBM Excavation through Pre-Existing Tie-Backs – Ship Canal Water Quality Project (SCWQP)

Francesco Chiappalon; LANE, Seattle, Washington, United States
Fabrizio Fara; LANE, Seattle, Washington, United States
Franco Gasperin; LANE, Seattle, Washington, United States

This document describes the challenging task of mining through tiebacks using a 21”8” diameter Tunnel Boring Machine (TBM) as part of the Ship Canal Water Quality Project. The mining operation involves navigating through 17 tie-backs that are evenly spaced at 8-foot intervals, with many intersecting the full face of the cutterhead. Detailed analysis and review of TBM parameters specific to this area have been conducted to ensure operational efficiency and safety. Hyperbaric interventions have been planned and coordinated, encompassing pre-mining preparations, continuous monitoring and adjustments during the mining process, as well as post-mining measures. The document highlights the complexity and importance of strategic planning and execution to successfully overcome the tie-back intersections during the mining operation.

 

10:45 am

Extended Application Ranges for EPB-Shields in Coarse-Grained Soils, the Lower Olentangy Tunnel Project Case History

Miriam Piemontese; Pini Group, Zurich, Zurich, Switzerland
Elisa Comis; Pini Group, Washington, District of Columbia, United States
Maria Chastka; Granite Construction, Columbus, Ohio, United States
David Chastka; Granite Construction, Columbus, Ohio, United States

The Lower Olentangy Tunnel (LOT) Project involves the construction of a 17,000 ft (5,200m) long, 12 ft (3.65m) internal diameter Combined Sewer Overflow (CSO) tunnel. The tunnel is excavated by using an Earth Pressure Balance (EPB) machine designed to cope with soft ground, weak rocks and water pressure. The project is located in the city of Columbus, Ohio and the main geotechnical hazards are related to the heterogenous soils and the low overburden in an urban environment. This paper focuses on the performance of the EPB first drive and the comparison between the design assumptions and the actual TBM performance during construction.

 

11:05 am

Tunnel Belt Applications for Long Distance Tunnels with Curvy Alignments

Marco Sonnenschein; H+E Logistik GmbH, Bochum, North Rhine-Westphalia, Germany

Belt conveyors for tunnelling are industry standard and key to high performance of TBM drives. Conveyors reduce traffic in the tunnel and increase safety in the tunnelling process. This paper will illustrate the state of the art of tunnel belt applications in very long and curvy tunnels like the Coxwell Bypass Tunnel Project in Toronto, Canada.

 

11:25 am

Long Haul TBM: Use of a Rebuilt Main Beam Machine at the DigIndy Tunnel System in Indianapolis, IN

Doug Harding; Robbins, Solon, Ohio, United States
Christian Heinz; J.F. Shea, Walnut, California, United States

TBMs can last for decades and be rebuilt project after project with proper maintenance. How successful can rebuilt TBMs be? At the DigIndy Tunnel System in Indianapolis, Indiana, USA, a rebuilt TBM was used to great effect. The 6.2 m diameter Main Beam, originally manufactured in 1980, bored 40+ km of tunnels and set three world records in its size class of 6 to 7 m, including a best month of 1,754 m. In this paper, the authors analyze the TBM rebuild, performance and lessons learned to make recommendations for future projects seeking to use rebuilt TBMs over long distances.

 

 

Monday, June 24 | Afternoon Sessions

1:30 pm – 4:30 pm

Case Histories: Shaft Excavation, Tunnel Rehabilitation & Challenges

Presidential C

Chairs: Jeramy Decker; Kiewit, Morgan Hill, CA
Ismail Karatas; HNTB, New York, NY

 

1:30 pm

Introductions

 

1:35 pm

Secant Pile Wall as Support of Excavation and Final Lining of a Major Underground Metro Station

Ashish Bhargava; AECOM, New York, New York, United States

Traditionally, secant piles have been utilized to provide temporary support during excavation for shafts and cut-and-cover tunnels. As an alternative, the secant piles can be included into the permanent structure, where they serve as the envelope sustaining the lateral loads and gravity of the permanent structure in addition to supporting the excavation during construction. This has several benefits, such as shorter building times and lower excavation costs. Recent construction of an approach structure and an underground station as part of Montréal, Canada’s Réseau Express Métropolitain (REM), one of the biggest transit systems in North America, was completed with remarkable success using this. In this paper, a case study based on a project that employed secant piles as the permanent liner is presented. Techniques to guarantee a watertight construction with over a century of service life are described, along with a variety of structural and waterproofing methods applied to create an economical design.

 

2:05 pm

TBM Rescue Shaft, Tunnel, and Relaunch in Karst Conditions

Dan Swidrak; Affholder Construction, O’Fallon, Missouri, United States
William Zietlow; Brierley Associates, Denver, Colorado, United States

Halfway through a 17,770-ft long stormwater tunnel, an 11-ft diameter TBM encountered a karst void below the Mississippi River in Missouri, resulting in significant inflow. It was decided that the TBM could not safely advance without external intervention. Low-mobility grout was pumped from the surface. A rescue shaft was constructed and a conventional tunnel with spiling support was mined back to the machine. The TBM was removed and a 14-ft diameter TBM equipped with probing drills was relaunched. Probing from the new TBM encountered one additional karst feature but the machine advanced after grouting and successfully completed the tunnel.

 

2:50 pm

Ground Freezing for Deep Shaft Excavation Shaft 18B-1 New York City Water Tunnel No. 3 New York, New York

Andrew Chegwidden; Keller, Rockaway, New Jersey, United States
Tara Wilk; Walsh Construction Company II, LLC, Little Falls, New Jersey, United States

Shaft 18B-1 is the second shaft to be constructed as a part of contract C547A along the New York City water supply system Tunnel No. 3. More complex than Shaft 17B-1, this site has an additional 30 m (100 ft) of overburden for a total excavation depth of approximately 78 m (256 ft) through water-bearing overburden soil and 145 m (475 feet) of gneiss bedrock to connect to the underlying Water Tunnel No. 3. Ground freezing was specified as the method to provide temporary earth support and ground water control for the overburden material. An extensive supplemental geotechnical investigation (SGI) and frozen soil testing program was performed to develop the design of a temporary ground freezing system, consisting of over 7,315 m (24,000 ft or 4.5 miles) of drilling for the installation of 95 freeze pipes. At the start of shaft excavation, the upper sandy silts strata was found to have an unprecedented low thermal conductivity, leaving the frozen soil face approximately 0.6 to 1 m (2-3 ft) behind the cutline. The ground freezing earth support needed to be augmented with ring beams and liner plates to support this soil face and allow for the excavation to proceed and be completed safely.

 

3:20 pm

Sumner Tunnel Rehabilitation

Joseph Rigney; Delve Underground, Burlington, Massachusetts, United States
David Nowak; Delve Underground, Burlington, Massachusetts, United States
Conrad Stacey; Delve Stacey Agnew, Darra, Queensland, Australia
Michael Beyer; Delve Stacey Agnew, Darra, Queensland, Australia
Chris Blanchard; J.F. White Construction Co., Framingham, Massachusetts, United States
John Czach; MassDOT, Boston, Massachusetts, United States

Originally constructed in the 1930s, the 1-mile-long Sumner Tunnel is 31 feet in diameter and carries traffic deep below Boston Harbor, connecting Boston and East Boston. This project includes both design and construction for the rehabilitation of the nearly 100-year-old tunnel. The primary work includes repairing advanced deterioration at the tunnel crown with new precast arches that will add protection and strengthening. The restoration also consists of upgrading the tunnel systems, including permanently removing 75% of the existing exhaust duct suspended over the roadway to improve the overall ventilation system capacity and performance.

 

3:50 pm

TBM Shield Abandonment beneath the Fraser River for Connecting Tunnel and River Riser of the Annacis Island WWTP New Outfall System

Ulf Gwildis; CDM Smith, Bellevue, Washington, United States
John Newby; CDM Smith, Burnaby, British Columbia, Canada
Ken Masse; Metro Vancouver, Burnaby, British Columbia, Canada
Guillaume Roux; Bessac, Delta, British Columbia, Canada

How to connect an effluent conveyance tunnel to riser shaft and diffuser arms of an outfall system is dictated by the ground conditions, which ideally include rock or soil strata of low permeability. Where such favorable conditions are beyond reach, both the complexity of designing and the risk of constructing this crucial system connection increase disproportionally. This paper describes the considerations that went into the approach of connecting a 5-m-diameter TBM drive with the in-river riser shaft of the Annacis Island WWTP New Outfall System in the highly permeable Fraser River sands at hydrostatic pressures exceeding 3 bar.

 

 

 


Design: Tunnel Lining Design

Presidential A

Chairs: Renee Fippin; Delve Underground, San Francisco, CA
Mark Trim; Delve Underground, Sydney, New South Wales, Australia

 

1:30 pm

Introductions

 

1:35 pm

Application of Post-Tensioning in TBM Tunneling: Case Study of JWPCP Effluent Outfall Tunnel Project in Los Angeles, USA

Ilkin Abdullayev; Mott MacDonald, Marina Del Rey, California, United States
Josue Garcia; Mott MacDonald, Paramount, California, United States
Mariana Soperano Capistran; Mott MacDonald, Long Beach, California, United States

The application of post-tensioning in segmental structures was introduced in the early 1900s and has been successfully applied in different types of structures including immersed tunnels, bridges, buildings, metro stations, and stadiums. There are, however, only five known circular concrete tunnel projects where the posttensioning approach has been adopted. This paper discusses the application of post-tensioning to mitigate the high internal operating pressures in an effluent outfall tunnel project 7 miles (11.3 km) long, currently under construction for the Los Angeles County Sanitation Districts (LACSD). This project will be the first use of post-tensioned segmental concrete tunnel linings in North America.

 

2:05 pm

Durability Design of CSO Tunnels

Irwan Halim; AECOM, Chelmsford, Massachusetts, United States
Robert Vail; AECOM, Atlanta, Georgia, United States

This paper describes a durability design approach for combined sewer overflow (CSO) tunnels to achieve 100-year life against exposure threats. The design conforms with relevant ACI codes including serviceability and maximum crack width criteria. The Life-365 model was used to assess chloride diffusion into concrete. An EPA approach was used to estimate corrosion loss of internal surfaces from hydrogen sulfide in wastewater. Groundwater and CSO fluid data were used to assess threats to exterior and interior structure surfaces. The durability design approach utilizes steel fiber reinforced tunnel lining, conventionally reinforced concrete with minimum clear cover requirements, concrete mix design specifications and protective linings.

 

2:50 pm

Optimization of Fire Design for FRC Tunnel Segments

Mehdi Bakhshi; AECOM, New York, New York, United States
Ali Haghighat; AECOM, New York, New York, United States
Verya Nasri; AECOM, New York, New York, United States
Nader Shahcheraghi; AECOM, New York, New York, United States

An accidental fire load is one of the major loads considered in design of segmental linings in transit tunnel. Typically, a two-dimensional coupled thermo-mechanical finite element analysis (FEA) is conducted. The conventional approach involves using standard fire curves (temperature-time curves) which can lead to a significant overestimation of fire load and tunnel lining thickness in metro tunnels. The focus of this paper is on the cutting-edge approach, using 3D computational fluid dynamics (CFD) analysis of real train fires in metro tunnels and coupled thermo-mechanical finite element analysis (FEA) to accurately and cost-effectively design fiber-reinforced concrete (FRC) segmental tunnel linings for large-scale metro projects.

 

3:20 pm

Fabrication and Installation of Americas First Post Tensioned Pre-cast Segmental Tunnel Liner

Madeline Mello; Dragados USA, Wilmington, California, United States
Nick Karlin; Dragados USA, Wilmington, California, United States
Bryce Scofield; Traylor Precast, LLC, Little Rock, California, United States
Michael Low; Traylor Precast, LLC, Littlerock, California, United States

The LA Effluent Outfall Tunnel is the first tunnel in the United States to incorporate post-tensioning into the precast segmental lining. Several unique components were integrated to ensure that the post tensioning could be carried out successfully in the tunnel, even concurrently with the TBM excavation. This also required the development of new processes both in the casting facility and in the TBM to ensure that the almost 3,700 rings could be successfully manufactured, threaded, stressed, and grouted. This paper will discuss the material selection, fabrication, and installation of, as well as lessons learned from, this first in country tunnel lining.

 

3:50 pm

Segmental Lining Design for the Hampton Roads Bridge-Tunnel

Botond Beno; Mott MacDonald, New York, New York, United States
David Watson; Mott MacDonald, New York, New York, United States
Danny Read; Mott MacDonald, Reading, Berkshire, United Kingdom

The Hampton Roads Bridge-Tunnel (HRBT) Expansion widens the existing I-64 four-lane bridge-tunnel corridor to eight lanes through construction of two parallel tunnels, interstate widening, and bridge expansions. The design-build contract was awarded to Hampton Roads Connector Partners with HDR and Mott MacDonald retained as lead designers in a Design Joint Venture. This paper will highlight some of the key challenges related to the design of the twin bored tunnels from spaceproofing, tunnel enabling works, segmental lining design and durability considerations.

 

4:20 pm

Raising the Roof – Successfully Overcoming a Starter Tunnel Roof Collapse Incident at the Westerly Storage Tunnel

Richard Depew; Northeast Ohio Regional Sewer District, Cleveland, Ohio, United States
Robert Auber; Northeast Ohio Regional Sewer District, Cleveland, Ohio, United States

The Westerly Storage Tunnel is a 25-foot diameter segmentally lined storage tunnel that is a major component of Northeast Ohio Regional Sewer District’s Project Clean Lake that is designed to capture 39 million gallons of untreated CSO overflows from entering Lake Erie. During the final stages of the project completion, a large-scale rock fall-out incident occurred during final lining installation operations at the down-stream end of the tunnel that extended beyond the designed primary support system. The paper outlines the level coordination and collaboration between Owner, Designed and Contractor to remediate the situation safely, timely and effectively.

 

 

 


Planning: Rehabilitation, Fire, Safety & Training

Presidential B

Chairs: Hamed Saghaeian-Nejad; Michels, Secaucus, NJ
Mahan Bigdeli; Arup, Golden, CO

 

1:30 pm

Introductions

 

1:35 pm

Why an Industry Education City for the Tunneling Sector

Ross Digby; Holmesglen Institute, Chadstone, Victoria, Australia

The Victorian Tunnelling Centre (VTC) has evolved its purpose from purely training workers, to a tunneling industry education city. The VTC has now focused its activities on the areas of technology; education and training; applied research; and career education were identified as the hubs around which activities would be conducted to create a tunneling industry education city. The VTC provides Australia’s tunneling industry with an education facility that not only provides labor training, but enables the industry to come together to meet, participate in product launches, undertake research, work with new technologies and promote tunneling careers.

 

2:05 pm

CFD Simulation of the Effect of Bifurcation on Fire Smoke Temperature and Toxic Gas Evolution in an Underground Mine Tunnel: A Case Study

Oluwafemi Salami; Missouri University of Science and Technology, Rolla, Missouri, United States

Conducting full-scale fire experiments in underground mines is difficult and expensive. Sometimes, it is impossible to carry out fire tests in mines due to the danger they pose to mine workers and the underground facilities. However, understanding the potential occurrence of fires in a mine and their dynamics is critical to developing an appropriate emergency evacuation plan, fire suppression, and firefighting techniques. In this study, a numerical fire model using computational fluid dynamics (CFD) with fire dynamics simulator (FDS) 6.7.6 was developed to examine the influence of tunnel bifurcation on maximum temperature beneath a tunnel ceiling. The model was validated using full-scale experimental data. The maximum ceiling gas temperature predicted using FDS and measured maximum smoke temperature during the experiment shows good agreement. The study shows that bifurcation could lower the maximum ceiling temperature of fire induced smoke in a subsurface environment. The findings from this study apply to the broader field of ventilation and fire life safety in tunnels and other underground environments.

 

2:50 pm

Tunnel Rehabilitation

Henry Russell Jr; HNTB, Boston, Massachusetts, United States

Over the last 25 years the rehabilitation of underground structures and in particular highway and rail tunnels has become an important part of underground engineering. Over that period the author has developed detailed procedures for the inspection and rehabilitation of tunnel structures and their associated systems. Most underground facilities that require rehabilitation in urban areas and are a major element of the infrastructure. The rehabilitation of these facilities requires that the facility be maintained in service during the repair/restoration work. As a result of these requirements, special procedures have been developed to facilitate the inspection, design, and implementation of the repairs. These procedures require the use of specialty products, construction methods, and in most cases prequalification of the contractor. This paper will discuss the procedures used for the inspection, design requirements, and in particular the use of specialty materials, construction practice, and current methodology using case histories to illustrate successful underground rehabilitation projects.

 

3:20 pm

Unique Aspects of Remote High Altitude Water Tunnel Repair

David Jurich; Mott MacDonald, Lakewood, Colorado, United States
Ed Perko; Busk Ivanhoe Water System Authority, Pueblo, Colorado, United States
Jacob Prezkuta; Drill Tech Drilling and Shoring, Parker, Colorado, United States

Numerous Colorado mountain tunnels that date to the late 1800s convey water to the farming and urban communities of the eastern Front Range. Repairs to these remote facilities, often located in public lands at altitudes of 11,000 feet or more, require detailed planning, close coordination with multiple agencies, and creative execution. Issues and solutions discussed include designing repairs in undocumented ground and support conditions, logistical challenges, work in a short summer construction window, stabilization of historically significant structures, and project delivery strategies. Examples that illustrate early contractor involvement, flexibility in design, and construction solutions are presented.

 

3:50 pm

Remediation of the Falls of Ground in a Water Conveyance Tunnel

Amir Karami; BGC Engineering Inc., Vancouver, British Columbia, Canada
Scott Munro; BGC Engineering Inc., Halifax, Nova Scotia, Canada

This paper focuses on remediation of a 3.6 km long water conveyance tunnel that suffered two large falls of ground (FoGs), one of which subsequently progressed to the ground surface, resulting in full collapse of the tunnel. The tunnel is part of a network of water conveyance tunnels and open channels that direct water into two turbines located in an underground powerhouse, originally constructed in the 1970’s. At the time of construction, the tunnel was partially supported with shotcrete or rock bolts, with no further ground support added since construction. Two sonar surveys in 2019 and 2021 identified two adjacent large FoGs in the tunnel, approximately 1.2 km from the tunnel outlet. Historical geological and geotechnical information indicated that the FoGs occurred within a 60 m wide fault zone. Remediation plans were developed, which included stabilization of the outlet channel, the portal, the tunnel leading up to the FoG areas (1.2 km length) and the FoG areas. Several remediation options were considered to restore the tunnel, including construction of a diversion tunnel to bypass the FoGs or remediation of the FoG areas with steel ribs and backfilling the void above the FoGs to surface.

 

 

 


Technology: Digital Technology

Presidential Chamber A

Chairs: Kaveh Talebi; Jay Dee Contractors, Inc., Livonia, MI
Jeff Brandt; Traylor Bros Inc., Hawthorne, CA

 

1:30 pm

Introductions

 

1:35 pm

Automation in Segmental Tunnel Lining Design: Case Study of the Northside Interceptor Tunnel Project (NSIT)

Bhoshaga Mitrran Ravi Chandran; AECOM, Oakland, California, United States
Kevin Huynh; AECOM, Oakland, California, United States
Irwan Halim; AECOM, Chelmsford, Massachusetts, United States

Tunnel segmental lining design constitutes a significant iterative process where modeling and numerical analysis are factors in deciding the number of segments, their dimensions, gasket placements, as well as the locations of dowels and bolts. Consequently, these modifications lead to revisions in the final drawing details. However, the current tunnel engineering practices lack systematic solutions that effectively bridge the gap between the iterative design process and efficient visualization of completed drawings due to the time-consuming nature of redrawing. This paper presents a pioneering application of AI-driven solutions including using Autodesk’s API, for the Northside Interceptor Tunnel (NSIT) Project. It showcases the automation of drawing design and the real-time visualization of modifications, thereby streamlining the drawing process.

 

2:05 pm

Determining Tunnel Clearance by Automating 3D Mobile Laser Profile Data

Ali Hafiz; Advanced Infrastructure Design, Inc., Hamilton, New Jersey, United States
Kaz Tabrizi; Advanced Infrastructure Design, Inc., Hamilton, New Jersey, United States
Joseph Rigney; Delve Underground, Burlington, Massachusetts, United States
Kevin Ruston; Delve Underground, Vancouver, British Columbia, Canada
James Dorta; Delve Underground, Sydney, Australia
Chris Blanchard; J. F. White Contracting Co., Framingham, Massachusetts, United States
Mike Keville; J. F. White Contracting Co., Framingham, Massachusetts, United States
Rich McCafferty; J. F. White Contracting Co., Framingham, Massachusetts, United States

Many existing tunnels have deteriorated as they age, requiring a massive amount of investment for their rehabilitation. The tunnel of interest in this paper is being rehabilitated by adding precast concrete arch panels under the existing concrete ceiling, and measuring the gap between them was the objective of this research. For this purpose, a mobile 3D laser/thermal scanner was used for scanning the tunnel, especially for the purpose of measuring its profile. To calculate the gap, the distance between the tunnel profile and the theoretical profile of the concrete arches was measured. Additionally, an in-house program was developed using MATLAB to automate the data processing to determine the above-referenced gaps. Results were provided in the form of heat maps showing the measured gap.

 

2:50 pm

Slurry Shield Cutterhead Torque Characterization using AI Machine Learning and Mechanics-Based Modeling

Mike Mooney; Colorado School of Mines, Golden, Colorado, United States

This paper documents an effort to explain cutterhead torque behavior observed during slurry pressure balance TBM tunneling through soft ground on the Los Angeles Clearwater project. AI machine learning and mechanics model-based learning was used to characterize cutterhead torque behavior including the TBM operating and ground parameters that influence cutterhead torque. Also, key parameters were from the slurry circuit data, including fines content, in-situ density, pore water fraction and solids content were included. The paper details what was learned using these new data-driven approaches as well as limitations with AI machine learning.

 

3:20 pm

BIM for Conventional Tunneling: The Sotra Link Project in Norway

Enrico De Panicis; Pini Group USA Inc., Washington, District of Columbia, United States
Elisa Comis; Pini Group USA Inc., Washington, District of Columbia, United States
Gianluca Bella; Pini Group SA, Lugano, Lugano, Switzerland
Matteo Giani; Pini Group SA, Lugano, Lugano, Switzerland
Guido Barbieri; Pini Group SA, Lugano, Lugano, Switzerland
Andrea Biagi; Webuild S.P.A., Bologna, Lugano, Italy

The Sotra Link Project is a major infrastructure project in Norway involving the design, construction, financing and maintenance of several underground and surface structures between Sotra Island and the city of Bergen, among them 23 tunnel portals, 12.5 km of tunnels and a 900 m long suspension bridge. This paper describes the benefits in applying a Building Information Modelling (BIM) approach to tunneling, from Early Design to the Detail Design Phase. The BIM application to the Sotra Link Project resulted in several improvements, such as efficient handling of clashes and inconsistencies, deeper understanding of effective design choices (reduction of errors), more efficient communication between designers, enhanced control of project quantities and costs. The advantages of the BIM approach during the ongoing Construction Phase are also explained.

Tuesday, June 25 | Morning Sessions

8:30 am – 11:45 am

Case Histories: Geotechnical and Contracting Cases

Presidential D

Chairs: Jon Isaacson; Brierly Associates, Milwaukee, WI
Robert Auber; NEORSD, East Cleveland, OH

 

8:30 am

Introductions

 

8:35 am

From Planning to Commissioning: A Complete Overview of the Northeast Boundary Tunnel Project

Filippo Azzarà; The Lane Construction Corporation, Cheshire, Connecticut, United States
Daniele Nebbia; The Lane Construction Corporation, Cheshire, Connecticut, United States
Moussa Wone; DC Water, Washington, District of Columbia, United States
Jeff Peterson; DC Water, Washington, District of Columbia, United States

The DC Water and Sewer Authority’s Long Term Control Plan includes tunnels, sewer separation, pumping station rehabilitation and green infrastructure to reduce combined sewer overflow (CSO) discharges to the District waterways. The Northeast Boundary Tunnel is a deep, large sewer tunnel that will reduce CSO discharges; significantly mitigate known chronic flooding in the Northeast Boundary drainage area and improve the water quality of the Anacostia River. This paper presents the unique combination of Owner and Contractor perspectives of the entire Project from conception through procurement, execution, and contract management, providing lesson learned, challenges encountered, and solutions implemented to deliver the Project successfully.

 

9:05 am

Quality Control of Deep Bedrock Tunneling in Urban Areas: A Case Study of Louisville MSD’s Ohio River Tunnel

Reese True; Black & Veatch, Louisville, Kentucky, United States
Alston Noronha; Black & Veatch, Louisville, Kentucky, United States
Mark Bradford; Black & Veatch, Indianapolis, Indiana, United States
Jacob Mathis; Louisville MSD, Louisville, Kentucky, United States

In June 2022, Louisville MSD completed a 6.5-km (4.0-mi), 6.1-m (20-ft.) diameter CSO conveyance and storage tunnel system located along the Ohio River in downtown Louisville, Kentucky. For large diameter shaft and tunnel construction, drill-and-blast operations among other methodologies were used in close proximity to federal, commercial, and residential properties with no impact to stakeholder infrastructure. As one of the first major tunneling projects in Louisville’s metropolitan area, this paper explores Black & Veatch’s rigorous geotechnical instrumentation monitoring program that provided quality assurance for local stakeholders and affirmed innovative tunneling solutions can be successfully executed in an urban setting.

 

10:20 am

Big Data in Design-Build: Hampton Roads Bridge-Tunnel Expansion Supplemental Site Investigation

Amanda Wachenfeld; Design Joint Venture (Mott MacDonald), Austin, Texas, United States
Frankie Perrone; Design Joint Venture (Mott MacDonald), New York, New York, United States
Brian Keaney; Design Joint Venture (HDR), Norfolk, Virginia, United States
Jean-Michel Charpentier; Hampton Roads Connector Partners, Norfolk, Virginia, United States
Martha Gross; Virginia Department of Transportation, Norfolk, Virginia, United States

The Hampton Roads Bridge-Tunnel (HRBT) Expansion widens the existing four-lane bridge-tunnel corridor to eight lanes through construction of two parallel tunnels, interstate widening, and bridge expansions. As part of the design-build contract, a supplemental geotechnical investigation was completed to support the design. The investigation for the subaqueous tunnel segment consisted of over 48,400 linear feet of drilling and 7,100 laboratory tests. This paper discusses the challenges of planning and executing a large-scale geotechnical investigation for underground works in a marine environment and the use of big data for effectively managing, interpreting, and transmitting data to the design-builder consistently throughout the investigation.

 

10:50 am

Ground Freezing with Liquid Nitrogen for TBM Cutterhead Maintenance

Joseph Sopko; Keller North America, Rockaway, New Jersey, United States
Xavier Dontigny; EBC Inc., Brossard, Quebec, Canada

For the REM (Réseau Express Métropolitain) project, a 2500 m tunnel was built using a tunnel boring machine (TBM) under the Montreal Pierre Elliott Trudeau Airport (ADM). Although the geology under the Montreal Airport (ADM) would have been suitable for an excavation with a hard rock machine, the first section required an earth pressure balance (EPB) TBM due to the soft soil located under wetlands. After excavating 280 m, the TBM was blocked in a transition zone of unconsolidated, water-bearing soils directly above the underlying bedrock. A free air intervention was not possible due to these geological conditions. After several failed attempts to create a slurry cake for hyperbaric interventions, a ground freezing system was designed and implemented, incorporating angled pipes drilled from outside the wetlands to directly in front of the cutterhead. This paper discusses the engineering required to form a frozen, water-tight zone in front of the cutterhead using liquid nitrogen. It also describes the complex method of replacing the disc cutters while holding the ground freezing system active in a manner protecting the health and safety of the workers.

 

11:20 am

Contractual Practice in SEM/ NATM – Tunneling in Austria and Germany

Richard Gradnik; BeMo Tunnelling GmbH, Innsbruck, Tyrol, Austria
Wolfgang Holzer; Brenner Basistunnel BBT SE, Innsbruck, Tyrol, Austria
Stefan Auderer; BeMo Tunnelling GmbH, Innsbruck, Austria, Austria
Lukas Erkurt; BeMo Tunnelling GmbH, Innsbruck, Tyrol, Austria

SEM/ NATM Tunneling contracts in Austria and Germany are usually tendered applying unit price contracts. The purpose of this paper is to show how contractual problems are resolved in these countries. The focus will be put on describing the theoretical approach, several case studies will show how contractual problems were dealt with on site.

 

11:50 am

Lessons Learned after Completion of the Michigan I75 Design-Build Resiliency-Improvement Tunnel

David Mast; AECOM, Cleveland, Ohio, United States
Brian Hagan; Jay Dee Contractors, Inc., Livonia, Michigan, United States
Kaveh Talebi; Jay Dee Contractors, Inc., LIvonia, Michigan, United States
Amanda Foote; AECOM, Newburgh, Indiana, United States
Jason Edberg; Great Lakes Water Authority, Detroit, Michigan, United States
Irwan Halim; AECOM, Chelmsford, Massachusetts, United States

On June 14, 2023 Jay Dee Contractors’ Tunnel Boring Machine (TBM) “Phoenix” holed through and completed mining the second drive of the I-75 Segment 3 Storage and Drainage Tunnel. Completion of the tunnel came only after overcoming several challenges, including a groundwater intrusion event which deposited thousands of cubic yards of wet ground material into the tunnel. This paper will discuss the events which delayed completion of the tunnel by over nine months, the risk management and construction approaches assumed by the Design-Build team during bid, several challenges faced by Design-Build teams when building stormwater resilience tunnels using traditional Department of Transportation standards, and recommendations for improving risk allocation and proposal documents for future similar Design-Build tunnel projects.

 

 

 


Design: Challenging Design Issues

Presidential A

Chairs: Mike Wongkaew; AECOM, Seattle, WA
Thomas Martin; Gall Zeidler, Ashburn, VA

8:30 am

Introductions

 

8:35 am

Evaluating Options in Design of the Akron Northside Interceptor Tunnel (NSIT) Tunnel Diversion and Flow Control Structure

David Mast; AECOM, Akron, Ohio, United States, Heather Ullinger;
City of Akron, Akron, Ohio, United States, Amanda Foote; AECOM, Akron, Ohio,
United States, Dominick Mandalari; AECOM, Akron, Ohio, United States

The City of Akron will construct the Northside Interceptor Tunnel (NSIT) project to control and reduce combined sewer overflows. One component of the project is a large diameter tunnel diversion / flow control structure that will facilitate tunnel storage, divert dry weather flow to the treatment plant, and divert large wet weather events that are greater than the tunnel capacity to the Cuyahoga River. The structure is designed to pass up to 1.2 billion gallons per day of flow and includes floatables screening. This paper will discuss project background, factors that influenced shaft location, and options evaluated to manage the large design flows.

 

9:05 am

Overcoming Design Challenges on the Ohio River Tunnel to Improve Water Quality in Pittsburgh, PA

Kimberly Kennedy; Allegheny County Sanitary Authority, Pittsburgh, Pennsylvania, United States
Michael Lichte; Allegheny County Sanitary Authority, Pittsburgh, Pennsylvania, United States
Zhenqi Cai; Mott MacDonald, Pittsburgh, Pennsylvania, United States

The Ohio River Tunnel is the first of three combined sewer overflow tunnels to be constructed under Allegheny County Sanitary Authority’s Clean Water Plan. The project consists of a total of approximately 5.5 miles of 18-ft and 14-ft finished diameter, segmentally lined deep rock tunnels and smaller diameter dewater and flow connector tunnels, as well as 8 deep flow drop and access shafts varying from 25-ft to 70-ft in finished diameter and 130-ft to 170-ft in depth. This paper describes the project components and the primary engineering challenges faced during design, including tunnel alignments and shaft site optimization with tight right-of-way constraints and multiple railroad and highway crossings. Assessment of tunneling methodology as well as tunnel and shaft designs and constructability included overcoming 5-bar hydrostatic pressure, abrasive bedrock, and the selection of the appropriate support of excavation systems in high-permeability alluvial soils adjacent to the Ohio River.

 

10:20 am

Tunnel Design for When H2O meets FeS2 Underground

Adam Bedell; Stantec, Cleveland, Georgia, United States
Jim Finley; Stantec Consulting, Fort Collins, Colorado, United States
Eric Schrader; Lynchburg Virginia Department of Water Resources, Lynchburg, Virginia, United States

The CSO 52 Storage Tunnel and Pump Station project consists of 4,700 ft of hard rock tunnel, 2 intakes, and a 6 MGD wet pit pump station. During the geotechnical investigation, it was determined that the host geology contained abundant sulfides. The purpose of this paper is to detail the investigation and subsequent determination that acid producing materials would affect the project during construction as well as long-term exposure of tunnel lining and permanent components during the operational life cycle of the tunnel and pump station. Details regarding the interaction between tunnel components and the acid producing material are also provided.

 

10:50 am

Design Development of the I-35 Capital Express Central Drainage Tunnels

James Parkes; Schnabel Engineering, Owings Mills, Maryland, United States
Mark Kroncke; Schnabel Engineering, Longmont, Colorado, United States
Dan Goodin; BGE, Inc., Austin, Texas, United States
Joseph Goessling; Texas Department of Transportation, Austin, Texas, United States

The I-35 Capital Expressway (CapEx) Central Drainage Tunnels will serve as a stormwater collection system for the forthcoming I-35 Capital Express Central reconstruction project through downtown Austin, Texas. The schematic level concept design included three tunnels, 10 to 14 ft ID, totaling 26,000 LF. Constructability reviews during design development indicated issues with the concept design including phasing of construction, conflicts with future retaining walls, staging area concerns, and significant mixed face tunneling. The design was updated to mitigate these risks. The revised design includes two tunnels, both 22-ft ID and totaling 33,000 LF, that will be mined almost entirely in rock.

 

11:20 am

Reconnecting Urban Landscapes through Highway Lidding and Tunneling: A Comprehensive Study on Methodologies, Benefits, and Safety Considerations

Katie Theis; HNTB Corporation, New York, New York, United States
Bernd Hagenah; HNTB Corporation, New York, New York, United States
Petr Pospisil; HNTB Corporation, New York, New York, United States
Christina Lauzon; HNTB, New York, New York, United States

Lidding over or tunneling existing transportation infrastructure is currently under review in several U.S. cities. The main reasons for this are the use of the created space for urban development, the reduction of noise and exhaust fumes for the residents, and, thus, a significant increase in the quality of life. The main aspects to be considered during the planning process are (1) total investment and operational costs, (2) impact of construction works on current traffic, (3) safety and fire protection, and (4) socio-environmental issues. The paper presents some basic planning principles, and experiences of recent urban highway coverages are shared.

 

11:50 am

Tunneling Through Reef Structures: Identification, Characterization, and Potential Impacts

Ike Isaacson; Brierley Associates, Milwaukee, Wisconsin, United States
Michael Miller; Citizens Energy Group, Indianapolis, Wisconsin, United States
Jarek Trela; Illinois State Geological Survey, Anna, Wisconsin, United States

Despite reef structures being relatively common in carbonate rocks around the world, tunneling experience in reefs is extremely rare. Impacts and risks associated with reef tunneling through these geologic features were also relatively unknown. A new reef was encountered during construction of the Lower Pogues Run Tunnel in Indianapolis, exposed over 5,000 linear feet along the alignment, resulting in adverse impacts on construction. Analysis of investigation data and construction from this encounter provide insight into the identification and characterization of reefs along tunnel alignments as well as the potential impacts on construction for future tunneling within reef structures.

 

 

 


Planning: Underground Project Delivery

Presidential B

Chairs: Phaidra Campbell; JCK Underground, Seattle, WA
Bill Bracken; Obayashi, Burlingame, CA

 

8:30 am

Introductions

 

8:35 am

Rehabilitation of the Rawah Ditch Tunnels

Ryan Marsters; Lithos Engineering, Golden, Colorado, United States
Adam Pring; Lithos Engineering, Denver, Colorado, United States

The Rawah Ditch is a mountainous water supply diversion which supplies Larimer County, Colorado with water since 1903. The ditch includes two historic tunnels excavated by drill and blast through a gneissic rock buttress. Both rock tunnels were failing with annual convergence. After a snowshoe-accessed field investigation, finite element modeling, and an alternatives analysis, a 54” diameter HDPE pipe was inserted within each tunnel and the annulus filled. The project was implemented in an Alternative Delivery contract lasting five months from field investigation through procurement and construction.

 

9:05 am

The Anomalies of the Purple Line Extension, Section 1, Los Angeles

Richard McLane; Traylor Bros., Inc., Long Beach, California, United States
Hans van de Vrugt; OneAtlas, San Diego, California, United States
James Corcoran; Traylor Bros., Inc., Evansville, Indiana, United States
Joseph DeMello; Los Angeles County Metropolitan Transportation Authority, Los Angeles, California, United States
Eric Carlson; OneAtlas, Auston, Texas, United States

The Los Angeles County Transportation Authority’s Purple Line Extension Phase 1 is a $3.12 billion (USD) de-sign-build, underground heavy rail project, connecting an existing station at Wilshire Boulevard and Western Avenue and extending west 3.92 miles under Wilshire Boulevard and terminating approximately 550 feet west of Wilshire / La Cienega Station. The project alignment runs through the heart of the world famous La Brea Tar Pits and one of the world’s largest urban oil fields. This paper presents a case history of the planning, design, and construction efforts to achieve successful construction of the bored tunnels through Reach 3 of the alignment. Further, this paper outlines the proactive partnership between the owner, Los Angeles County Metro (Metro), the Design Builder, Skanska-TraylorShea Joint Venture (STS), and Southwest Geophysics who provided the geophysical services. Specifically, the project included background review of historic site data (e.g., oil field maps, building foundation plans, historic aerial photographs, etc.), geophysical demonstration testing to ascertain the capability of borehole magnetics to detect oil wells, directional drilling of thousands of feet of horizontal and vertical boreholes, collection of high resolution magnetic gradiometer data along vertically and horizontally cased boreholes as well as the collection of surface magnetometer data, discovery (“ground truthing”) of detected geophysical anomalies, and abatement of potential obstructions within the tunnel alignment.

 

10:20 am

Early Contractor Involvement and Observational Method Supported with Artificial Intelligence for Equitable Risk Management

Kumar Bhattarai; HNTB Corporation, Frisco, Texas, United States
David Hatem; Donovan Hatem LLP, Boston, Massachusetts, United States

Effective risk management in major subsurface projects involves ways to mitigate adverse impacts to final design and construction approaches due to changed subsurface conditions. An Early Contractor Involvement (ECI) collaborated with Observational Method will be an effective contractual tool to address risk developed due to encountering differing site conditions. Observational Method (OM) can further be supported with artificial intelligence (AI) technologies with automated data-driven decision-making features in risk mitigation and implementation of proper design and construction approaches. This paper presents collaborative applications of ECI, OM, machine learning, and risk baselining in risk management and productivity enhancement in tunneling projects.

 

10:50 am

The Anacostia River Tunnel System in Washington DC: Construction and Performance of One the World’s Largest CSO Reduction Infrastructures

John Beesley; DC Water, Washington, District of Columbia, United States
Jeffrey Peterson; DC Water, Washington, District of Columbia, United States
John Cassidy; Greeley and Hansen, Washington, District of Columbia, United States
Martino Scialpi; Pini Group USA Inc., Washington DC, District of Columbia, United States

The DC Clean Rivers Project is DC Water’s ongoing program to capture and treat combined sewer overflows (CSOs) during rainfall before they reach the District waterways. The Anacostia River system was designed to reduce CSOs into the Anacostia River and includes the Blue Plains Tunnel, Anacostia River Tunnel, First Street Tunnel, and Northeast Boundary Tunnel. A portion of the Anacostia River system was commissioned in March 2018 and the final component, the Northeast Boundary Tunnel, was placed in operation on September 15, 2023. This paper provides a summary of the experience gained during construction of this +$2.9 billion project, an overview of the system performance since its activation in 2018, and a look-ahead to the next phase of the DC Clean Rivers program: the Potomac River Tunnel.

 

11:20 am

P3 Delivery for the I-75 Storage and Drainage Tunnel, Detroit, Michigan

Mark Dubay; Michigan Department of Transportation, Southfield, Michigan, United States
Gerald Luttman; WSP USA, Detroit, Michigan, United States
Elizabeth Dwyre; WSP USA, Pittsburgh, Pennsylvania, United States
Anvesha Dogra; WSP USA, Detroit, Michigan, United States
Wei Hu; WSP USA, Detroit, Michigan, United States

The I-75 Modernization Project (Segment 3) just north of Detroit, MI is being delivered as a Design-Build-Finance-Maintain (DBFM), which is a Public Private Partnership (P3). The project includes design and reconstruction of 5.5 miles of freeway, including a depressed section with a 20,630-ft long, 14.5-ft inside diameter, up to 100-ft deep stormwater tunnel, multiple drop shafts, and a pump station. The project also includes a maintenance term of 25-years. This is the first time MDOT has used a P3 delivery method for a major highway and tunnel project. This paper describes the development of the P3 documents, including performance-based tunnel and shaft technical requirements, and the approach to project risk management, financing, and insurance coverage.

 

11:50 am

Value Engineering for the Shoreline Consolidation Sewer: An Example of Collaboration between Owner, Engineer, and Contractor

Adrian Naranjo-Castillo; Mott MacDonald, Chicago, Illinois, United States
Christopher Petta; Mott MacDonald, Cleveland, Ohio, United States
Eric Zarobila; Northeast Ohio Regional Sewer District, Cleveland, Ohio, United States
Colin Irwin; Warde and Burke Tunneling Inc., Columbus, Ohio, United States

The Shoreline Consolidation Sewer is a CSO control project in Cleveland, Ohio that requires the installation of 5,000 feet of 72-inch inside diameter pipe using microtunneling methods. After award, the contractor submitted a value engineering proposal to eliminate two deep shafts and install the tunnel in two drives instead of four. In an example of successful collaboration, owner, contractor, and engineer worked together during the initial construction stages to modify the design and update the contract documents. This paper examines the importance of flexible requirements in contract documents and a collaborative environment between all parties to successfully deliver a project.

 

 

 


Technology: Construction Innovation

Presidential C

Chairs: Jimmy McGauley; Barnard, Bozeman, MT
Angel Del Amo; Aldea, Yorba Linda, CA

8:30 am

Introductions

 

8:35 am

Innovations in the Production of Tunnel Lining Segments

Stefan Medel; Herrenknecht AG, Schwanau, Baden-Wurttemberg, Germany

As a pioneer Herrenknecht started in 2018 to automate the production of tunnel lining segments. Since then, many automation processes became state of the art. Robots cleaning and oiling the moulds, hydraulic units opening and closing them fully independently. Artificial Intelligence (AI) controls the works and ensures the quality requirements. Data management has become a massive tool from a simple data collector towards a control and optimization tool. Sensors controlling concrete maturity and supporting the precast team to optimize the concrete mix. These state of the art and new innovations will be presented in this paper.

 

 

9:05 am

Innovative Approach to Install Precast Segmental Lining in Lieu of Cast-In-Place in Starter Tunnels

Eren Kusdogan; JayDee, Toronto, Ontario, Canada
Ehsan Alavi; JayDee, Toronto, Ontario, Canada
Georges Cote, Everest Equipment Co., Ayer’s Cliff, Quebec, Canada

The City of Toronto’s Coxwell Bypass Tunnel is currently being constructed by North Tunnel Constructors (NTC) ULC, a joint venture of Jay Dee Canada, C&M McNally Tunnel Constructors and Michels Canada. This project includes construction of approximately 10.5 km of 6.3 meter finished diameter rock tunnel, five 20 meter diameter storage shafts and eleven tunnel connection drop shafts, along with associated deaeration and adit tunnels. 120 m of Starter tunnel and 70 m of Tail tunnel were excavated with roadheaders to help with the launch of the TBM and as part of the contract base scope work. JayDee Canada in Collaboration with Everest Equipment Co. developed an innovative approach to design and build a stand-alone Ring Machine Erector nicknamed Enterprise to erect precast segmental lining in Starter and Tail tunnels in lieu of Cast-In-Place concrete. This paper describes the design and provides feedback on the innovative procedure used to install the rings.

 

10:20 am

Subsea Tunnel Geotechnical Investigations Pre and Post Contract Award-A Plan for Success

Gary Peach; Mott MacDonald, Wheatley, Oxfordshire, Qatar
Khalid Saif Al-Khayareen; Ashghal, Public Works Authority, Doha, Qatar
Vigil Fernandez; PORR, Doha, Al Wakrah, Qatar

The Musaimeer pump station and outfall project (MPSO) is in Doha Qatar. This technical paper will discuss and explain the three major stages of geotechnical investigation employed. Stage one the tender geotechnical data and how this was used to design the TBM and identify various areas of risk. Stage two was the selection of supplementary geotechnical investigation methodologies. Stage three was the geotechnical investigation by specialist equipment installed on the TBM and providing further data on a real time basis as the TBM was advancing. Analysis of all the data will be provided along with the lessons learned.

 

10:50 am

Overcoming Sustainability Challenges for Design and Construction of Urban and Long-Distance Tunnels

Eric Wang; Hill International, Inc., Fords, New Jersey, United States
Bernd Hagenah; HNTB Corporation, New York, New York, United States

New tunnels of significant alignment lengths such as mountain tunnels, base tunnels, as well as beneath urban centers pose unique environmental challenges. This paper highlights key environmental considerations for planning, design, construction, and operations by sharing lessons-learned from the authors’ extensive project experience on these types of tunnels. Discussion of unique constraints include limited right-of-way, ventilation and emergency egress during the construction phase and revenue service, safety and security, and protection of existing structures. Practical approaches and applied innovative state-of-the-art solutions addressing distinct sustainability challenges and unique requirements are shared from US and international project examples.

 

11:20 am

The Importance of Wastewater Treatment Plants for Tunneling Projects

Gino Vogt; Herrenknecht AG, Schwanau, Baden-Wurttemberg, Germany

Water is one of the most important resources of our planet. Unlike many other natural resources, water cannot be substituted by anything and must therefore be handled with the utmost care. Depending on the region and the possible shortage of water, the importance of water increases even further. Water consumption is not the only factor. In the construction industry, water pollution from auxiliary and operating materials and processes as well as other contaminants and their resulting load on wastewater play an important role. The sources for wastewater on tunneling construction sites are various: Washing water, seepage water accumulating in construction pits, tunnel water, water used in the slurry circuit in fluid-assisted tunneling methods or water from concrete work and stone cutting – all these waters are contaminated with a range of pollutants like solids, hydrocarbons, heavy metals, etc. These contaminants can be removed or treated/ reduced with the help of specifically designed wastewater treatment plants (WTPs). After the treatment the cleaned water can be either, in best case, reused on the construction site itself or discharged into water utilities like the available sewer or river pin respecting their discharge requirements. Due to dwindling water resources globally, the continuously rising discharge limits and the ever more important aspect of sustainability the use of WTPs on tunneling construction site will be indispensable. In this paper, it will be presented how these systems are designed and work, what advantages they offer environmentally as well as financially and what to look out for when planning and implementing such a system onto jobsite.

 

 

Tuesday, June 25 | Afternoon Sessions

1:30 pm – 4:30 pm

Case Histories: TBM Performances and Challenges I

Presidential D

Chairs: Tolga Togan; WSP, Newark, NJ
Carlo Cattelan; Technopref, Montreal West, PQ

 

1:30 pm

Introductions

 

1:35 pm

Ultra-Long Tunnel Drive with TBM for the Construction of the Project York Potash Mine

Dr. Karin Bäppler; Herrenknecht AG, Schwanau, Baden-Wurttemberg, Germany
Werner Burger; Herrenknecht AG, Schwanau, Baden-Wurttemberg, Germany

A new polyhalite fertilizer mine is currently being developed in the UK by Anglo American Crop Nutrients. The project includes the construction of a Mineral Transport Tunnel almost 37kms long to house a conveyor belt that will move polyhalite from the production shaft at the mine to a materials handling facility at the port. The project sets a new standard in terms of an ultra-long tunnel drive and sustainable, environmentally friendly and efficient material transport. The paper highlights in particular the 5.94m diameter TBM in use for the construction of the ultra-long tunneling section.

 

2:05 pm

Microtunneling to the Rescue: Increasing Capacity and Replacing Aging Interceptor Sewers Due to Rapid Growth in Irving, Texas

Brian Glynn; Freese and Nichols, Inc., Leawood, Kansas, United States
Amanda Powers; Freese and Nichols, Inc., Dallas, Texas, United States
Daniel Huffines; Freese and Nichols, Inc., Frisco, Texas, United States
Robert Sauceda; City of Irving, Texas, Irving, Texas, United States
Mike Garbeth; Super Excavators, Inc., Menomonee Falls, Wisconsin, United States

This paper will review the evaluation performed for the Cottonwood & Hackberry Creek Wastewater Interceptor Improvements Project to replace two separate aging and undersized interceptor sewers by either open cut construction or trenchless construction methods. A case study will be discussed for the utilization of microtunneling to avoid a deep open cut excavation within a landscaped roadway median to construct nearly a mile of new 60-inch interceptor sewer in an urban area adjacent to an environmentally sensitive riverine area, while minimizing the permitting and environmental impacts of construction, and minimizing the impacts to residents and vehicular traffic and restoration requirements.

 

3:00 pm

Pawtucket CSO Tunnel Design Build – Construction Project Updates

Irwan Halim; AECOM, Chelmsford, Massachusetts, United States
Stephane Polycarpe; CB3A, Pawtucket, Rhode Island, United States

The Narragansett Bay Commission Phase III CSO Program includes construction of the 11,600-foot long, 30foot ID, deep rock Pawtucket Tunnel in Rhode Island. This paper provides an overview of the Design Build Project features and highlight some of the important design considerations, features, and innovations, including geologic conditions and related TBM design, and deep shaft and tunnel segment designs. The paper provides the most recent updates on some of the project construction activities including TBM tunnel progress and retrieval schemes, tunnel pump station and deep vertical shaft liner installations, SEM construction, and microtunneling for the longest adit using Fiberglass Reinforced Polymer Mortar pipes.

 

3:30 pm

TBM Breakthrough in Pressurized Conditions – Ship Canal Water Quality Project (SCWQP)

Francesco Chiappalone; LANE, Seattle, Washington, United States
Fabrizio Fara; LANE, Seattle, Washington, United States
Franco Gasperin; LANE, Seattle, Washington, United States
Marco Invernizzi; GO Construction PRO, LLC, Seattle, Washington, United States

As part of the Ship Canal Water Quality Project, 2.7-mile Combined Sewer Overflow tunnel is excavated with a 21.5-foot diameter EPB Tunnel Boring Machine. Due to the difficult geological and hydrogeological conditions, the tunnel is excavated maintaining a ground support pressure between 1 and 3 bar imposing significant challenges to the projects. The first part of the paper describes the general characteristics of the project while the second part focuses on the challenges and technical details of the pressurized breakthrough that took place in a deep shaft excavated in urban environment as part of the project.

 

4:00 pm

Construction of an Underground Niche for TBM Repair and Permeation Grouting in Flooded Shaft

Fabrizio Fara; Lane Construction, Seattle, Washington, United States
Marco Invernizzi; GoConstructionPro, Little River Academy, Texas, United States

The Ship Canal Water Quality Project includes a 2.7-mile, 18-ft and 10-in internal-diameter tunnel that extends from Ballard to Wallingford, two popular neighborhoods in the West of Seattle. During the TBM Main drive a 12’ x 12’ boulder with variable strength up to 47,000psi was encountered resulting on significant damages to the Cutter Head. The first part of this paper describes the design and construction of an underground recess in front of the TBM to create a safe working environment for the TBM repairs. The second part describes an injection campaign performed to seal an unforeseen water inflow appeared during the excavation of the 11 Avenue Diversion Structure.

 

4:30 pm

Parallel Thimble Shoal Tunnel: Challenging TBM Assembly and Launching in an Existing Island

Ruben Piqueras; Dragados USA, Virginia Beach, Virginia, United States
Santiago Martínez; Dragados USA, Virginia Beach, Virginia, United States
Jorge Vázquez; Dragados USA, Virginia Beach, Virginia, United States
Xavier Manjarín; Dragados USA, Virginia Beach, Virginia, United States
Juan Luis Magro; Dragados, Madrid, Madrid, Spain

The Parallel Thimble Shoal Tunnel project involves the construction of a bored tunnel under Thimble Shoal Channel in Chesapeake Bay (VA), between two artificial islands and parallel to the existing tube tunnel, built in the sixties. It will be the first transportation tunnel constructed in the Mid-Atlantic region using a Tunnel Boring Machine (TBM), a 44-foot-diameter Earth Pressure Balance (EPB) named “Chessie”, manufactured by Herrenknecht, and which was assembled at the CBBT’s southernmost island, with extremely limited room, live adjacent traffic, and difficult access. “Chessie” was successfully launched in February 2023 and this paper describes this complex and challenging process.

 

 

 


Design: Innovative Designs

Presidential A

Chairs: Saeid Rashidi; HATCH, Belle Mead, NJ
Michael Deutscher; Jacobs, Attleboro, MA

 

1:30 pm

Introductions

 

1:35 pm

Tunnel Euralpin Lyon Turin CO8 – Design of Temporary Support Profile of Base Tunnels and Cross-Passages

Francesc Rich; Pini France Engineers S.A.S, Saint Ouen, Paris, France
Barbara Bitetti; Pini France Engineers S.A.S, Saint Ouen, Paris, France
Elisa Comis; Pini Group USA Inc., Washington, District of Columbia, United States
Giuseppe Ragazzo; Systra-SWS, Torino, Piemonte, Italy
Julien Pepiot; Demathieu Bard Construction, Paris, France
Stefano Lione; Tunnel Euralpin Lyon Turn (TELT), Collegno, Italy

The new Lyon-Turin railway project involves the construction of a 57 km twin-tube tunnel between France and Italy. Pini France (project leader) and Systra-SWS are the designers of Construction Site 8 (CO8). This part of the project includes the construction of the tunnel portal on the Villard-Clément platform, two 2.8 km long tubes of the base tunnel in the direction of Saint Martin la Porte, the cross-passages between tubes and the niches. This paper presents the general approach followed to design the temporary support for the base tunnel, crosspassages, and technical rooms. The design of the temporary support accounts for the variability of the ground and water conditions, the excavation attended behavior, the construction planning and the identified geological hazards that could be encountered along the alignment. Particular attention is paid to the intersections between the tunnels both in terms of numerical modelling and construction methods and phases. Two types of intersections are present in the project: the intersections between the cross-passages and the base tunnel and the intersections between the base tunnel and the niches. 3D models have been developed for the tunnel intersections.

 

2:05 pm

To Swell or Not to Swell – Design of Underground Structures in the Presence of Swelling Clays

Daniel Maine; Brierley Associates, Austin, Texas, United States

Swelling clay soils have been problematic to many types of infrastructure in the United States. However, their impact on underground construction is often misunderstood. The use of swell pressures in design of initial tunnel and shaft support lacks proper guidance and is often mis-interpreted. This paper provides insight and guidance on how to implement a geotechnical investigation program to determine if swelling soil exists at a site and how it impacts the design of temporary support systems for underground projects. An example is provided for how swell pressures were incorporated into the design of an initial support system for a rib and lagging tunnel system and problems that occurred.

 

3:00 pm

Experimental Characterization of Large Diameter Tunnel Lining Radial Joint Rotation Behavior

Mike Mooney; Colorado School of Mines, Golden, Colorado, United States
Haotian Zheng; Colorado School of Mines, Golden, Colorado, United States

This paper summarizes the results of an experimental program conducted to characterize the moment-rotation behavior of skewed flat radial joints from large diameter (45 ft) tunnel lining. Both positive and negative joint moment-rotation behaviors were measured experimentally using two-segment joint combination assemblies. The results are compared to closed form methodologies used by designers, e.g., the Janssen method. The differences in observed and model behavior are discussed within the context of design practice.

 

3:30 pm

Impact of High-Speed Operation on Tunnel Planning

Bernd Hagenah; HNTB Corporation, New York, New York, United States
Petr Pospisil; HNTB Corporation, New York, New York, United States
Colin Santangelo; HNTB, New York, New York, United States

This paper explores the profound implications of high-speed train operation on tunnel planning, specifically investigating ongoing high-speed rail projects in California and Texas. The paper delves into the crucial considerations for designing high-speed rail tunnels, including selecting tunnel sections based on aerodynamic factors, which impact traction power requirements and pressure comfort. The paper also examines the need for emergency stations, maintenance access, and comprehensive safety and rescue concepts to address train incidents. Drawing from international high-speed rail projects, it shares valuable experiences and lessons learned to promote efficient and secure tunnel designs for high-speed train operations.

 

4:00 pm

Threading the Needle: Design and Construction of the Parallel Thimble Shoal Tunnel Project

Sandeep Pyakurel; Mott MacDonald / Chesapeake Tunnel Joint Venture, Arlington, Virginia, United States
Frankie Perrone; Mott MacDonald / Chesapeake Tunnel Joint Venture, New York, New York, United StatesMitchell Gerdau; Mott MacDonald, Virginia Beach, Virginia, United States
Eric Crocker; Dragados USA/ Chesapeake Tunnel Joint Venture, Virginia Beach, Virginia, United States
Joan Casado Ortega; Dragados USA/ Chesapeake Tunnel Joint Venture, Virginia Beach, Virginia, United States

The Parallel Thimble Shoal Tunnel (PTST) project is a part of the Chesapeake Bay Bridge-Tunnel (CBBT) complex. The project involves the construction of a two-lane bored tunnel under the Thimble Shoal Channel between Portal Island #1 (the southernmost island) and Portal Island #2. The new PTST will be the first transportation tunnel constructed in the Mid-Atlantic region by a tunnel boring machine (TBM). This paper describes the design and construction of the tunnel approach structure in an open marine environment with the strategies employed to overcome the various construction challenges. The project is unique since the entire tunnel approach structure is built on a very limited area within an open marine environment without any reclamation of the existing island.

 

 

 


Planning: Underground Project Risk

Presidential B

Chairs: Paul Savard; MWRA, Ashland, MA
Reza Lotfi; COWI, Mc Lean, VA

 

1:30 pm

Introductions

 

1:35 pm

Integration of Century Old Mont Royal Tunnel into Montreal New Light Rail Transit Network

Mohammad Motallebi; AECOM, Montreal, Quebec, Canada
Behrouz Esmaeilkhanian; AECOM, Montreal, Quebec, Canada
Verya Nasri; AECOM, New York, New York, United States

Réseau Express Métropolitain (REM) is the new Light Rail Transit (LRT) network of Montreal, Canada. This new LRT network uses a century-old Mont Royal Tunnel (MRT) to connect Downtown Montreal to the north side of the Island of Montreal by passing through Mount Royal Mountain. This railway double track horseshoe tunnel is approximately 5 km (3.1 mi.) long, 8.8 m (29 ft.) wide and 5.5 m (18 ft.) high, with a constant 0.6% grade. Due to different geological characteristics of the surrounding ground, varied from hard rock to soft soil, different cross sections and excavation methods were adopted for construction of this tunnel. In order to use MRT in the modern transit system, the tunnel needed to be inspected, rehabilitated and be compliant to the recent safety standards. This paper presents a summary of history and characteristics of the existing tunnel plus the implemented steps to upgrade the tunnel. It includes the details of the structural inspection and rehabilitation methods of the tunnel. Further, this paper summarizes the procedures for the space proofing, construction of the separation center wall, and the tunnel enlargement. It also de-scribes parts of complications encountered during the construction and solutions implemented to tackle these issues.

 

2:05 pm

Risk Mitigation for the Big Walnut Sewer Tunnel Construction in Columbus, Ohio

Irwan Halim; AECOM, Chelmsford, Massachusetts, United States
Heather Marsh; Marsh-Wagner, Jacksonville, Florida, United States
Rob Herr; City of Columbus Department of Sewerage & Drainage, Columbus, Ohio, United States

This project will expand sanitary sewer within the City of Columbus. It consists of 2.5 mile long, 72-inch finished diameter pipe grouted inside 10.8-foot diameter tunnel excavation in shale. This paper describes the multi-faceted geotechnical exploration to minimize the underground risks. The tunnel will cross below a buried valley with minimum cover of highly weathered rock. The risk mitigation to cross the valley includes contingencies and cost allowances. Provisions to prevent impact on adjacent groundwater resources will be described. Latest construction updates will be provided including contractor alternate shaft support and pre-excavation probing to mitigate tunneling risk below the valley.

 

3:00 pm

Durability Design and Construction for Underground Facilities

Wern-Ping Chen; Jacobs Engineering, Boston, Massachusetts, United States

Durability risks for underground facilities can be underestimated during design phase as compared to well-known geological risks. However, unclear durability requirements can result in construction schedule delay and change orders. Unlike bridges or buildings, a unified underground durability code or standard does not exist. This paper will provide a durability approach for underground facilities, including degradation modes, mitigations, and compliance measures during construction. In addition, this paper will address how to clearly specify durability requirements in a contract document to reduce disputes during construction and discuss key durability tests that are time consuming and will impact construction schedule if not timely planned.

 

3:30 pm

Hydraulic Testing and Monitoring – (How) Can it Help in Tunnel Construction? A Case Study of the Varberg Tunnel, Sweden

Åsa Fransson; University of Gothenburg and WSP, Sweden, Gothenburg, Västra Götaland, Sweden

Water is a key resource and tunneling’s impacts on groundwater largely relate to inflow and drawdown caused by construction and operation of underground infrastructure. Constructing fully sealed tunnel lining systems or alternatively pre and post grouted drained systems are examples of solutions to reduce and mitigate impacts to acceptable levels. Understanding which is the optimal solution from an engineering, environmental and sustainability perspective requires the geological and hydrogeological setting thoroughly be understood. Based on a Swedish tunnel project, this paper gives examples of how hydraulic testing and monitoring can help assess impacts and help develop appropriate strategies to manage them.

 

4:00 pm

Surface Water Supply Project – Segment B3 Long Tunnel – Houston, TX

William Hodder; Jay Dee Contractors, Katy, Texas, United States
Nate Long; Jay Dee Contractors Inc. dba, Houston, Texas, United States
Phil Rhodes; Jay Dee Contractors Inc. dba, Houston, Texas, United States
Sergio Flores; Black & Veatch, Houston, Texas, United States
Tim McQueary; HB Trenchless, Houston, Texas, United States

The Surface Water Supply Project Segment B3 is a 4 miles section of tunnel that will run East-West in Houston TX, from Hopper St to I-45. The tunnel will be mined by using a 128” Dia refurbished 1987 Lovat Tunnel Boring Machine capable of operating in Open or EPB mode. The tunnel will be temporarily supported with ribs and lagging and a 96” Dia pipe will be grouted into place. All four miles of this project are within Petroleum Pipeline Easements. The project includes seven shafts, 2000’ of tunnel in potentially petroleum contaminated ground, crossing the Hardy Toll Rd, I-45, the Union Pacific Railroad Right of Way and multiple oil and gas pipeline crossings. This paper summarizes the planning and drive performed to date.

 

4:30 pm

JWPCP Effluent Outfall Tunnel in Los Angeles, California – Anticipated Challenges and Slurry TBM Performance in the Soft Ground Section of the Alignment

Martino Scialpi; PINI Group USA Inc., Washington, District of Columbia, United States
Miriam Piemontese; Pini Group AG, Zurich, NA, Switzerland
Roberto Schuerch; Pini Group SA, Zurich, NA, Switzerland
Claudio Cimiotti; Dragados USA, Costa Mesa, California, United States
Matt Kendall; Dragados USA, Wilmington, California, United States
Nick Karlin; Dragados USA, Wilmington, California, United States

The Los Angeles, California JWPCP effluent outfall tunnel will transport secondary-treated effluent from the Joint Water Pollution Control Plant in Carson to the White Point Manifold. Upon completion, through ground conditions ranging from soils to hard rock, the tunnel will be approx. 7 miles (11km) long with a finished internal diameter of 18-ft (5.5m). This paper will present the Tunneling Condition Assessment Report (TCAR) and Tunnel Operation Plan (TOP) developed prior to construction, as well as the actual TBM performances achieved along the northern portion of the alignment in soft ground, shallow cover, and beneath a densely urbanized area.

 

 

 


Technology: Innovative Solutions

Presidential C

Chairs: Bryce Grimm; Kiewit, Omaha, NE
Maria Chastka; Granite, Columbus, OH

 

1:30 pm

Introductions

 

1:35 pm

Evolving Underground Communication and Connectivity

Tom Michaud; Strata Worldwide, Sandy Springs, Georgia, United States
Michael Rispin; Strata Tunneling, Sandy Springs, Georgia, United States
Ian Turner; Strata Products Worldwide EU GmbH, Saarbrücken, Saarland, Germany
Rob Albinger; Strata Worldwide, Canonsburg, Pennsylvania, United States

Data transmission, communication, tracking, and the connection of equipment such as gas detectors, cameras, and collision avoidance systems in today’s tunnel industry are critical pieces of the constructor’s infrastructure. Reliability, flexibility, redundancy and cost-effectiveness are key in selecting and implementing integrated systems. Both wired and wireless components are used to deliver custom solutions and can involve interconnectivity between backbones. Systems integration is important as the industry adopts proven technologies from other industries. Case studies are given showing how tailor-made approaches deliver needed functionality, with varying degrees of complexity, in various classifications of environment, in order to meet a project need.

 

2:05 pm

XXL Pipe Jacking: Technological Aspects of Large-Diameter and Long-Distance Drives

Peter Schmäh; Herrenknecht AG, Schwanau-Allmannsweier, Baden-Wurttemberg, Germany

As tightened safety regulations increasingly limit the options of segment lining in diameters below 4 m, pipe jacking has partially taken over. During the last decades, a growing number of large-diameter and long-distance pipe jacking projects has been completed. Experienced contractors successfully use the technological capacity of MTBM equipment. Continuous further development of technological features for pipe jacking is key to overcome feasibility limits and to meet increased project requirements. The overall aim is to provide clients and contractors with safe and economical solutions for successful projects. International milestone projects and latest innovations will be shared in this presentation.

 

3:00 pm

Multimodal Machine Learning Technologies in Tunnel Geotechnical Applications

Kumar Bhattarai; HNTB Corporation, Frisco, Texas, United States
Gunjan Bhattarai; Platinum AI, Frisco, Texas, United States

Applications of machine learning and robotics in the tunneling industry are still nascent. Research and development are ongoing in TBM guidance; prediction of TBM cutter wear and tunneling induced ground deformations; and robotic arms for segment installation, inspection, cleaning, and maintenance of TBM cutting tools. This paper presents a case study of geological profile reconstruction using multimodal machine learning. The results from this study can aid the development and application of multimodal AI technologies to generate data reports and geological profiles in real time, taking voice recordings, photos, or videos obtained directly from the field as inputs.

 

3:30 pm

Alternative Delivery and Trenchless Methods used to install 60,000LF of Pipe on the Bay Park Force Main Project

George Gutierezz; Northeast Remsco Construction, Wall Township, New Jersey, United States
Carl Pitzer; Thompson Pipe Group, Grand Prairie, Texas, United States
Jeff LeBlanc; Thompson Pipe Group, Grand Prairie, Texas, United States

The Bay Park Conveyance Project was one of the largest microtunneling and rehab projects in the United States at the time of completion. The completed project conveys treated water from the South Shore Water Reclamation Facility located in Nassau County, New York, which currently discharges an average of 50 million gallons per day (MGD) of treated water into Reynolds Channel, to the Cedar Creek Water Pollution Control Plant (WPCP) ocean outfall pipe. The pipe carrying treated wastewater was installed approximately 20–60 feet below the surface. The treated wastewater is conveyed via microtunnel construction of a 2-mile long force main from the South Shore Water Reclamation Facility to an existing aqueduct under the Sunrise Highway, the rehabilitation of an 7.3-mile stretch of the aqueduct via sliplining, and construction via microtunnel of a 1.6-mile-long force main to connect the rehabilitated aqueduct to the existing Cedar Creek Water Pollution Control Plant (WPCP) outfall, which discharges and diffuses treated water three miles offshore in the Atlantic Ocean. This paper will review the Design-Build requirements, the chosen innovative solutions during planning for the micro tunneling portion of the project and review the microtunnel construction on the project.

 

4:00 pm

LTA 219 Project: Multiple Unique Tunneling Solutions in One Subway Package in Singapore

Yann Rouillard; Bessac Inc., St Jory, France
Alix Thierart; Bessac Inc., Singapore
Bernard Catalano; Bessac Inc, Canonsburg, Pennsylvania, United States

Bessac’s presence in Singapore started in 2014 with the construction of the Thomson metro line, which includes 18 miles of twin-bore tunnels and 22 stations split into 17 construction packages. Bessac joint venture was allotted the T219 lot. The works include the construction of: a new 660-foot (200- meter) long transfer station, two parallel 19-foot (5.8 m) ID tunnels and a pedestrian underpass. The urban context and the very soft ground stratum imposed to utilize unusual tunneling techniques, from upgrading a slurry TBM to a high-density slurry TBM to launch with very low cover and canopy pipe roofing completed with a MTBM without retrieval shaft.

 

Wednesday, June 26 | Morning Sessions

8:30 am – 9:40 am

Case Histories: TBM Performances and Challenges II

Presidential D

Chairs: Josh Morton; Granite, Vernon Hills, IL
Casey Underwood; Dragados, Las Vegas, NV

 

8:30 am

Introductions

 

8:35 am

TBM Tunneling between the Westridge Marine Terminal and the Burnaby Terminal in British Columbia

Mohamed Maghari; Kiewit Infrastructure Co., San Jose, California, United States
Nick Joens; Kiewit infrastructure Co., Omaha, Nebraska, United States
Jeff Reid; McNally, Hamilton, Ontario, Canada

The Burnaby Mountain Tunnel was an integral part of the Trans Mountain Expansion Project. General Contractor, Kiewit Ledcor TMEP Partnership (KLTP), contracted with McNally Construction to build an underground tunnel between the Burnaby and Westridge Marine terminals under Burnaby Mountain. The pipeline was constructed within a 2.6-kilometre tunnel, eliminating the need to run the pipeline over the mountain and minimizing community impacts. The complexities of this Project led to multiple innovations, including the design of a Tunnel Boring Machine (TBM) capable of excavating through mixed-faced conditions concurrently thus allowing the Project team to complete the tunnel with limited geotechnical information.

 

8:55 am

Lessons Learned from Larger Diameter Waterview Road Tunnel to Smaller Diameter CRL Rail Tunnel in Auckland, New Zealand

Wataru Okada; WSP, Auckland, Auckland, New Zealand
Ritesh Mahajan; WSP, Sydney, New South Wales, Australia
Antoni Kuras; WSP, Sydney, New South Wales, Australia
Matthew Bilson; WSP, Sydney, New South Wales, Australia

The Waterview Tunnel comprises twin 2.4 km long 13.1 m internal diameter three lane road tunnels in Auckland, New Zealand. The City Rail Link (CRL) is a 3.45 km long, 6.24 m internal diameter twin rail tunnel underneath Auckland’s city center. This paper presents an overview of the tunnel geometry, segmental lining configurations, geometric constraints, performance criteria and functional requirements for the large diameter Waterview Tunnels and smaller diameter CRL tunnels. Other key aspects, which include sustainability, innovations, construction performance and practical aspects are discussed and compared. Lessons learnt from these mega tunneling projects are also presented.

 

9:15 am

Historic Storm Drain Tunneling Revealed by Los Angeles Metro Subway Construction

William Hansmire; WSP USA, Los Angeles, California, United States
Jason Choi; WSP, Los Angeles, California, United States
Christophe Bragard; Traylor Bros., Inc., Long Beach, California, United States

This case history provides a physical benchmark of tunneling technology progress comparing an old hand-mined tunnel to a modern 20-ft-diameter EPB TBM that mined in the same ground. This rare opportunity to see how tunnels were constructed many years ago occurred when an old 10-ft-diameter storm drain tunnel in the way of Los Angeles subway construction was demolished and replaced with Hobas (fiberglass) pipe. Steel rib and lagging initial support was exposed showing solid-sawn 2” x 12”x 48” redwood lagging. This paper documents the as-built old tunnel, how it was successfully replaced, and some lessons learned.

 

9:35 am

A 108-in Storm Tunnel Underneath Active Taxiways and Apron at O’Hare International Airport

Mark Stephani; HNTB Corporation, Chicago, Illinois, United States
Adam Lamanna; HNTB Corporation, Chicago, Illinois, United States
Tim Benson; Super Excavators Inc., Menomonee Falls, Wisconsin, United States
Carolina Martinez-Gutierrez; Chicago Department of Aviation, Chicago, Illinois, United States

The Lower Concourse C Extension (LCE) 108-in Storm Sewer consists of a 2,797-foot long, 27 to 55-foot deep, 108-in I.D. storm sewer tunnel. Situated beneath active taxiways and a terminal apron at O’Hare International Airport (ORD), the tunnel diverts flows from existing storm sewers located within the footprint of a future satellite concourse. The project was delivered via Construction Manager at Risk (CMAR) as part of Chicago Department of Aviation’s (CDA) ongoing O’Hare 21 Capital Program. This paper presents project details, multiple stakeholder coordination, subsurface risks and challenges, TBM performance, and impacts to existing infrastructure.

 

 

 


Design: Design of Underground Spaces

Presidential A

Chairs: Marion Saler; Dr. Sauer, Reston, VA
Brian Negrea; McNally, Westlake, OH

 

8:30 am

Introductions

 

8:35 am

Risk Assessment and Large Diameter Segmental Lining Design in Swelling Ground

Sergio Sanchez; AECOM, Madrid, Madrid, Spain
Giuseppe Gaspari; AECOM, Mississauga, Ontario, Canada
Michael Mains; AECOM, Burnaby, British Columbia, Canada
Carlos Alvarez; AECOM, Madrid, Madrid, Spain

Extensive record of tunnels excavated with SEM (sequential excavation method) in swelling grounds exists in literature: global experiences include successful tunneling both through clayey and rock masses with time dependent deformation. However, TBM (tunnel boring machine) use in swelling conditions with high water pressures (EPB, earth pressure balance, machines or slurry shields) is much less documented, considering the lower expected impact due to the limited stress relief and operations under saturated conditions. This paper summarizes a number of studies conducted as part of the risk assessment and detailed design of a large diameter TBM tunnel in variable and challenging geological conditions. The tunnel alignment is driven through mixed face conditions including swelling soils and clayey soft rocks, prone to intense time-dependent deformations. The paper also describes the approach adopted for the design of pre-cast segmental lining subject to both swelling actions and high seismic loads, due to the regional active tectonic faults. The design of this lining included a detailed parametric study performed to handle the existing uncertainties related with ground characterization, potential deconfinement and complex geological configurations.

 

8:55 am

Design & Construction Monitoring of a Road Tunnel under Very Low Cover in the SNCF South-East European Technicentre in Paris

Bénédicte Robert; Pini Group, Saint-Ouen, Seine-Saint-Denis, France
Edoardo Trivellato; Pini Group, Lugano, Tessin, Switzerland
Yassine Lahmadi; SNCF Réseau, La Plaine Saint-Denis, Seine-Saint-Denis, France
Christian Chereau; SNCF Réseau, La Plaine Saint-Denis, Seine-Saint-Denis, France

Within the framework of the adaptation of the South-East European Technicentre (Technicentre Sud-Est Européen – TSEE), SNCF Voyageurs appointed Pini with the project management mission (MOE) for the design and construction monitoring of a road tunnel. This investment has a dual function: during the site transformation phase, it facilitates the work logistics (and shorten traffic flows); and in the operating phase, it is intended to ease all movements on the site over the long term. This is a limited-length gallery (50 meters) to be performed in conventional excavation below Poniatowski Avenue (Paris 12e). The excavation, crossing the entire width of the boulevard, constitutes a major challenge, given the very low coverage (less than 5.5 m), and the surrounding main infrastructures. The same project mission includes the design of the tunnel accesses, via reinforced-concrete frame structures. The targeted design questions several aspects of its execution framework, and particularly, continuous operation must be guaranteed to the neighboring networks during the works. The installation of an umbrellapipe all along the excavation profile, the progression in divided sub-sections, and the implementation of a complex monitoring system are hence key elements for limiting and controlling any deformation. An exhaustive 3D finite element modelling was performed, taking into account the detailed phasing of construction (pre-support, excavation in divided section, preliminary support and definitive lining), to dimension the structures, and, overall, to analyze the impacts on the neighboring structures and facilities. During the execution phase (planned for mid-2024), monitoring activities with back-analyses as close as possible to the works are planned.

 

9:15 am

West Gates Deicing Industrial Waste Pond Expansion Project: Tunnel Design Challenges at Denver International Airport

Alex Warren; Lithos Engineering, Denver, Colorado, United States
Dylan Fawaz; Lithos Engineering, Fort Collins, Colorado, United States
Nick Tessitore; Burns & McDonnell, Centennial, Colorado, United States
Ryan Marsters; Lithos Engineering, Denver, Colorado, United States

The West Gates Deicing Industrial Waste Pond Expansion project at Denver International Airport seeks to expand utilities to accommodate additional terminal gates. The project includes six tunnel crossings beneath taxiways and runways with lengths ranging from 239 to 2,025 linear feet. Excavation methods include shielded tunnel boring machines and steerable auger boring. Designed initial support includes liner plate, steel ribs and lagging, steel casing, and Fiberglass Reinforced Pipe and ranges in size from 24” to 132”. This paper will discuss challenges associated with the overall layout and design of the project, including contingencies to protect critical infrastructure. In addition, a construction update is provided.

 

9:35 am

Preliminary Ground Characterization for the Mokelumne Aqueducts Resiliency Project (MARP) Tunnel

Kenneth Johnson; WSP USA, San Francisco, California, United States
Marshall McLeod; East Bay Municipal Utilities District, Oakland, California, United States
Stephen Klein; WSP USA, San Francisco, California, United States
Emma O’Hara; WSP USA, San Francisco, California, United States
Samuel Gambino; East Bay Municipal Utilities District, Oakland, California, United States

The Mokelumne Aqueducts Resiliency Project (MARP) involves construction of a 16.5-mile tunnel across the Sacramento-San Joaquin Delta (Delta) to replace the existing surface aqueduct pipelines with more resilient conveyance. The tunnel will be bored in Pleistocene-age alluvium at elevations between 100 to 130 feet below mean sea level. At this depth ground conditions are significantly stiffer and denser than surficial soils and will mitigate potential seismic hazards related to liquefaction, ground shaking and flooding that could arise from potentially damaged levees. The heterogeneous soil deposits at tunnel depth consist of interbedded layers of stiff to very stiff clay and silt, and dense to very dense clean sand and silty sand.

 

 

 


Planning: Underground Construction and Challenges

Presidential B

Chairs: Anthony Gallo; VMR Civil LLC, Mineola, NY
Victoria Encapera; Black & Veatch, Kansas City, MO

 

8:30 am

Introductions

 

8:35 am

Grouting Aggressive Ground in Qatar

Jacek Stypulkowski; ASHGHAL. The Public Works Authority (PWA) of the State of Qatar, Doha, Qatar
Hernan Fernandez; PORR-HBK-MIDMAC, Doha, Qatar
Volkan Salepciler; Parsons International, Doha, Qatar
Khalid Saif F S Al-Khayareen; Public Works Authority, Doha, Qatar

Wakrah and Wukair Drainage Tunnel (WWDT) is 13 km long with a 4.5 m ID sewer water tunnel about 50 to 60 m below ground surface. Integral to the project are several adits with provisions for future connections as well as four work shafts, four intermediate access shafts, ancillary hydraulic structures, and an Odor Control Facility. The shaft depths range from 50 to 60m. The project is constructed in aggressive ground with aggressive ground water. The construction activities require years of pumping and disposal of the ground water during tunneling operations as well as construction of permanent structures in shafts. Grouting of the corrosive rock mass in corrosive groundwater for the WWDT has been described in detail.

 

8:55 am

SAWS W-6 Upper Segment: Construction for Future Generations

Henry Leighton; CAS, San Antonio, Texas, United States
Jason Swartz; Black & Veatch, San Antonio, Texas, United States
Gerardo Gomez; San Antonio Water System, San Antonio, Texas, United States

San Antonio has experienced sustained growth for decades, putting increased pressure on existing wastewater infrastructure. In June 2013, San Antonio Water System (SAWS) reached a Consent Decree agreement that requires significant improvements to the wastewater system over a 10-year period to reduce Sanitary Sewer Overflows. One of the critical projects was the W-6 Upper Segment Tunnel project to reduce sanitary sewer overflows on an existing sewer main running through Lackland Airforce Base. The replacement project consisted of a new tunnel nearly 29,000 LF of primarily 104” FRP. The project also includes nine shafts and multiple trenchless crossings to make near surface connections to the new works.

 

9:15 am

Holding Back the Bay: Performance of Jet Grout in Hydraulically Placed Fills

Jeb Pittsinger; Mott MacDonald, Westwood, Massachusetts, United States
Frank Perrone; Mott MacDonald, Virginia Beach, Virginia, United States
Mitchell Gerdau; Mott MacDonald, Virginia Beach, Virginia, United States
Roger Escoda Estelrich; Dragados USA/ Chesapeake Tunnel Joint Venture, Virginia Beach, Virginia, United States
Joan Casado; Dragados USA/ Chesapeake Tunnel Joint Venture, Virginia Beach, Virginia, United States
Jose Raul Martinez; Dragados USA/ Chesapeake Tunnel Joint Venture, Virginia Beach, Virginia, United States

The existing Chesapeake Bay Bridge-Tunnel complex is being expanded to include the Parallel Thimble Shoal Tunnel. This will be a subaqueous bored crossing between two islands constructed for the original 1960s immersed-tube tunnel. Jet grouting was employed by the Chesapeake Tunnel Joint Venture (CTJV) to provide watertight base plugs, launch and retrieval blocks for the tunnel boring machine (TBM), a TBM canopy to limit ground movement, and a retaining wall to enable off-island excavation: all within hydraulically placed sands. This paper will review the design and construction challenges, including soil permeability and recharge, grout communication, installed grout strengths, and remediation requirements.

 

9:35 am

Repair of a Failed Reinforced Concrete Adit Tunnel with Carbon Fiber Wrap

Ryan O’Connell; Kilduff Underground Engineering, Denver, Colorado, United States
Daniel Willis; Merco Engineering Contractors, Lebanon, New Jersey, United States

An 8-foot tall horseshoe adit tunnel located within an abutment of the Mount Morris Dam in Mount Morris, NY required repair of a failed reinforced concrete liner. The adit tunnel is entirely founded within highly weathered shale bedrock units, which induced unloading stress on the original tunnel liner. An epoxy-impregnated carbon fiber fabric wrap manufactured by Sika was chosen to repair the failed adit tunnel liner. Kilduff Underground Engineering completed the design of the tunnel repair utilizing both empirical and numerical methods. Merco Engineering Contractors completed the injection of chemical grout and repair liner installation.

 

 


Technology: Design Innovations

Presidential C

Chairs: Bradford Miller; MWRA, Chelsea, MA
Alex Williams; Schnabel, Okemos, MI

 

8:30 am

Introductions

 

8:35 am

Collapsible Columns to Limit Earth Flow Loading

Taehyun Moon; HNTB, New York, New York, United States
Kenneth Xu; HNTB, New York, New York, United States
Raymond Sandiford; HNTB, New York, New York, United States

Tunnel approach structures situated in slow moving earth flows are subjected to significant earth pressures. The authors have developed a system, utilizing collapsible concrete columns, that limits such loading. The system uses an array of collapsible concrete columns in front of the structure to absorb downslope movement and limit-imposed loads. This concept has been modelled using 3D FEM analyses and a rudimental lab test. For implementation, the collapsible columns would be prefabricated in strengths to mimic the soil strength profile. This concept has merit, and analytical results demonstrate that collapsible columns are a viable means to limit loading.

 

8:55 am

Using Convolutional Neural Network (CNN) for Automated Defect Classification in Tunnel Lining Inspections

Saleh Behbahani; Purdue University, West Lafayette, Indiana, United States
Jamal Rostami; Colorado School of Mines, Golden, Colorado, United States
Tom Iseley; Purdue University, West Lafayette, Indiana, United States

Tunnels and underground infrastructures assets, like all assets, deteriorate with time. At some point, they reach the end of their useful life. Therefore, frequent inspections, higher levels of maintenance, and rehabilitation are needed to address loss of life and safety concerns. The repair cost of tunnels will increase if maintenance of tunnels is not satisfactory and timely. Historically, tunnel inspections have primarily relied on visual and manual procedures. Due to their time-consuming nature and susceptibility to human error, there is a demand for alternative automated techniques that can enhance efficiency and reliability in tunnel inspection. By utilizing a tunnel scanning system, such as laser scanner and thermography, or photogrammetry system, tunnel inspection cost, time, and personnel can be reduced. The goal of this study is to utilize deep convolutional neural networks (CNNs) for automated identification of defects in tunnel lining inspection. This paper presents a framework to classify two types of defects in tunnel lining (water leakages and cracks) using CNNs. The CNNs were trained and tested using 4,608 images. The Precision, Recall, and F1 Score were each 99.6 %, confirming the viability of this approach in the automated defect identification in tunnel lining.

 

9:15 am

Revolutionizing Australia’s Large Underground Infrastructure Projects with Digital Engineering

Elnaz Saminfar; Delve Underground, Melbourne, Victoria, Australia
Eric Westergren; Delve Underground, Mayfield Heights, Ohio, United States
Jeff Fontana; Delve Underground, Seattle, Washington, United States
Jae Bateman; Delve Underground, Sydney, New South Wales, Australia
Mark Trim; Delve Underground, Sydney, New South Wales, Australia

This paper presents a case study of two major Australian infrastructure projects that used digital engineering to facilitate design delivery: WestConnex Project (Rozelle Interchange), and Sydney Metro West (Eastern Tunneling Package). The paper presents project overviews and building information modeling (BIM) execution and focuses on modeling techniques, software utilization, data management strategies and how the digital models helped the design-build team mitigate impacts to schedule by identifying clashes between disciplines before the execution of work. Finally, it demonstrates the positive and transformative impact of digital engineering on the design and construction of large underground infrastructure projects and highlights its role in asset management throughout the project lifecycle.

 

9:35 am

Is the International Experience of Risk-based Decision Making for Road Tunnel Safety Applicable in the Unique US-American Regulatory Environment?

Bernhard Kohl; ILF Group Holding, Rum bei Innsbruck, Tyrol, Austria,
Arnold Dix; International Tunneling and Underground Space Association,
Monbulk, Victoria, Australia, Oliver Heger; ILF Consulting Engineers, Austria

This paper presents a case study of two major Australian infrastructure projects that used digital engineering to facilitate design delivery: WestConnex Project (Rozelle Interchange), and Sydney Metro West (Eastern Tunneling Package). The paper presents project overviews and building information modeling (BIM) execution and focuses on modeling techniques, software utilization, data management strategies and how the digital models helped the design-build team mitigate impacts to schedule by identifying clashes between disciplines before the execution of work. Finally, it demonstrates the positive and transformative impact of digital engineering on the design and construction of large underground infrastructure projects and highlights its role in asset management throughout the project lifecycle.

 

Wednesday, June 26 | Closing Plenary

10:30 am – Noon

Closing Plenary – Tunnel Vision

Presidential D

Chair: Rafael Castro, Principal, Schnabel Engineering, Valrico, FL
Louis Falco, Boston, MA

The Tunnel Vision session will have presentations from various owners and engineers regarding upcoming projects throughout North America.
James Morrison – Gateway Project
Anthony Pooley – Sound Transit Expansion, West Seattle & Ballard
Michael Lichte – ALCOSAN Clean Water Plan, Ohio River Tunnel
Matthew Crow – Los Angeles Metro Tunnel Projects
Giuseppe Gaspari – Canadian Tunneling Programs

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