Grouting work done earlier in the week was a possible cause of a bulge in the lining of a train tunnel under the River Thames. Two trains hit the bulge before the line was closed, but neither train derailed. [Source: New Civil Engineer]
Related Articles

Building the world’s longest tunnel tests advanced surveying technologies
The Gotthard Base Tunnel will eventually be a 35-mile rail tunnel through the famed Alps in southern Switzerland. So what does it take to survey the world’s longest tunnel? How about setting some 7,000 points […]

The Most Important Fridge On Earth
Today, Tuesday, February 26, 2008, the Svalbard Global Seed Vault is scheduled to start operating on the remote island of Spitsbergen, Norway in the Svalbard Archipelago. The location is only about 1000km (625 miles) from the North Pole. The Global Seed Vault will house duplicates of seeds from known species of plants from all over the world in case a natural or other disaster destroys the original species. [Editor] Read on for more details. Photo by Mari Tefre/Svalbard Global Seed Vault [/Editor]

Cologne Tunnel Collapse: Investigations Focus on Tiebacks and Groundwater
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)