Second Issue of International Journal of Geoengineering Case Histories [Official This Time]

California motorists can now avoid a dangerous and landslide-prone stretch of the Pacific Coast Highway, Devil’s Slide, through the tunnel bypass. This project has been a fascination of mine since the early days of GeoPrac.  […]

Excavation for the $700M Lake Mead Intake No. 3 Project was put on hold after tunneling encountered a fault carrying groundwater that flooded the excavation and submerged equipment. The flooding occurred over about 4-days, so […]

The latest information to come out of the collapse of a subway tunnel excavation in Cologne, Germany is that investigators are evaluating the ground anchors or tiebacks that were holding open the subway tunnel excavation. There doesn’t appear to be much information available to the public yet, and the New Civil Engineer article mostly quoted academics saying an anchor failure “could” have caused the collapse. Apparently at the time of the collapse, the excavation had reached the bottom depth after the slurry walls had been constructed along with the ground anchor system. Crews were supposedly working on the base slab which would have undoubtedly stiffened up the whole system. For what its worth, an anonymous comment left at the bottom of that article indicated that after half of the debris had been excavated, the diaphragm walls were still intact and without apparent displacement. So what other theories have been floated? Read on for more info.  (Image Credit: New Civil Engineer)

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