UndergroundStructuralGeneralEditorialsWinter 2025 Follow up on Early Strength Testing
Christoph Goss, PhD, PE, PMP, F.ASCE
Read MoreIn my last column, I discussed the need for early strength testing in underground shotcrete…
UndergroundGeneralEditorialsHow Do You Recruit for an Invisible Job?
Maria Chastka
Read MoreYou 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…
RepairUndergroundGeneralTraffic Repairs Using Low-Dust Shotcrete Material: Monitor-Merrimac Tunnel Project
Thomas Brennan
Read MoreHistorically, 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…
UndergroundStructuralGeneralShotcrete Placement for Initial Support: Climate Pledge Arena Tunnel Project
Mark Pinske, Elizabeth Lenker, and Paul Mockus
Read MoreThe 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
UndergroundStructuralGeneralShotcrete as Final Liner — Design Considerations
Andy Thompson
Read MoreThe 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…
UndergroundInternationalGeneralInitial and Final Shotcrete Linings for Edouard Montpetit Station of REM Project – 2024 Honorable Mention Project
Verya Nasri
Read MoreR.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.
UndergroundGeneralAnderson Dam Tunnel – 2024 Outstanding Underground Project
Brian Harris, PE, and Alex Folchi, PE
Read MoreDrill 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.
RepairUndergroundGeneralRelieving Water Pressure on Shotcrete Lining by Integrating a Drainage Mesh
Johnny Poulsen & Sergii Tabachnikov
Read MoreUnderground construction, especially a tunnel, is one of the most complex challenges in the field of civil engineering. Dolenco Drain is an innovative solution which addresses many of the difficulties with controlling or eliminating water pressure in an easy, safe, long-term, and cost-effective manner.
UndergroundStructuralGeneralEarly Age Strength Testing for Shotcrete: 2024
Christoph Goss, Norbert Fuegenschuh, Lauro Lacerda, Kevin Robertson, and Shaun Radomski
Read MoreFor improved safety in tunneling and mining projects that use shotcrete for ground support, early shotcrete strength should be evaluated by testing. Based on their range of effectiveness, two procedures stand out: The new Hilti BX 3-SCT stud driving method and the beam end tester.
UndergroundStructuralInternationalGeneralThe Application of Shotcrete in Shafts: Work Preparation and Construction Based on Various Projects in Central Europe
By Paul von der Hoeh, Norbert Fuegenschuh, Richard Gradnik
Read MoreShotcrete shafts often present unique challenges for construction projects. In many cases the construction method is different from the one used in the main tunnel (often using a TBM), presenting challenges recruiting experienced and certified personnel for the shaft works.