Look for the following Delve Underground presentations on the 2024 NAT Session Schedule:

Construction Phase Services for Australian and North American SEM Tunneling

Monday, June 24, 10:05 a.m.

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.

Presenters: Mark Trim and Sarah Wilson

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


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

Monday, June 24, 10:25 a.m.

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.

Presenter: Ritika Kundu

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


Sumner Tunnel Rehabilitation

Monday, June 24, 3:20 p.m.

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.

Presenters: Joseph Rigney and David Nowak

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

Determining Tunnel Clearance by Automating 3D Mobile Laser Profile Data

Monday, June 24, 2:05 p.m.

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.

Presenter: Ali Hafiz 

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


Revolutionizing Australia’s Large Underground Infrastructure Projects with Digital Engineering

Wednesday, June 26, 9:15 a.m.

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.

Presenter: Eric Westergren

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

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