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UndergroundStructuralGeneral2025 Carl E. Akeley Award: “Shotcrete as Final Liner – Design Considerations”

Andy Thompson

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The 20th annual Carl E. Akeley Award was presented to Andy Thompson for his article, “Shotcrete as Final Liner — Design Considerations,” which was published in Shotcrete magazine, Volume 27, Number 3, 3rd Quarter 2025. The article discusses how shotcrete (often called sprayed concrete) is

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UndergroundStructuralGeneralHumber College Station Shotcrete Construction: Design, Sustainability, and Execution – 2025 Outstanding Infrastructure Project

Ross King

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Humber College Station is located at the west end of the 6.4 mi (10.3 km) Finch West LRT, which includes 16 stops and two below-grade terminal stations. The Humber College Station is constructed below grade, however open to daylight, which presented unique logistical, structural, and

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UndergroundGeneralNew York City Grand Central Station New Passageway – 2025 Outstanding Underground Project

Louis Falco

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The prestigious Grand Central Station is located in a major hub center of New York City bound by East 42nd Street (south), Lexington Avenue (east), East 51st Street (north), and Madison Avenue (west). As one of the major hub centers…

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UndergroundStructuralGeneralCommentariesWinter 2025 Follow up on Early Strength Testing

Christoph Goss, PhD, PE, PMP, F.ASCE

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In my last column, I discussed the need for early strength testing in underground shotcrete…

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UndergroundGeneralCommentariesHow Do You Recruit for an Invisible Job?

Maria Chastka

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You can be working on a large-scale, technically challenging, resource-consuming project … and if it goes well, people will not even know you’re there. Herein lies one of the struggles the tunneling industry faces: If people aren’t aware the projects exist, they also don’t know there are jobs available…

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RepairUndergroundGeneralTraffic Repairs Using Low-Dust Shotcrete Material: Monitor-Merrimac Tunnel Project

Thomas Brennan

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Historically, the dust associated with dry-mix shotcreting caused hesitation in projects in urban or live traffic environments; however, recent innovations in low-dust materials have significantly changed planning considerations…

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UndergroundStructuralGeneralShotcrete Placement for Initial Support: Climate Pledge Arena Tunnel Project

Mark Pinske, Elizabeth Lenker, and Paul Mockus

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The Washington State Coliseum was an arena built for the 1962 Seattle World’s Fair. More than half a century later, in 2019, a $1B construction program began to redevelop and expand the arena. The redeveloped building, with a new name — Climate Pledge Arena — retains the historical roof, but

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UndergroundStructuralGeneralShotcrete as Final Liner — Design Considerations

Andy Thompson

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The use of shotcrete placement (often called sprayed concrete) for the final permanent structural lining of underground structures and facilities continues to increase around the world. Where non-uniform shapes are required, shotcreting provides…

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UndergroundInternationalGeneralInitial and Final Shotcrete Linings for Edouard Montpetit Station of REM Project – 2024 Honorable Mention Project

Verya Nasri

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R.seau Express M.tropolitain (REM) is an automated (driverless) light-rail transit (LRT) system in Montreal, Canada. It features 67 km (42 mi) of double tracks and 26 stations. Once completed, it will be the 4th longest automated LRT transportation system in the world.

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UndergroundGeneralAnderson Dam Tunnel – 2024 Outstanding Underground Project

Brian Harris, PE, and Alex Folchi, PE

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Drill Tech Drilling & Shoring, Inc. performed Sequential Excavation Method (SEM) tunnel construction with geometric cross sections consisting of 19 ft to 24 ft (5.6 to 7.3 m) diameter tunnels (including wide span intersections) for the Anderson Dam Tunnel Project.