Controversy was swirling around last week’s Seattle Mayoral primary race as incumbent Mayor Greg Nickels supports the tunnel to replace the Alaskan Way Viaduct and challenger Michael McGinn wants to tear down the viaduct and […]
Seven new design contracts were issued today for the Crossrail project including four central London Stations and three significant portals. According to the New Civil Engineer, the project is being called "Europe’s Largest Construction Project". […]
Kansas City, Mo. (Aug. 5, 2009) – The U.S. Army Corps of Engineers (USACE) has selected Black & Veatch as the design engineer for the McCook Reservoir Main Tunnel. The new tunnel will connect the future McCook Reservoir to Chicago’s Deep Tunnel system, which is aimed at improving water quality in area rivers and Lake Michigan and reducing flood risk for the city of Chicago and suburban communities. [Editor] Read on for the rest of the press release. Photo copyright Black and Veatch[/Editor] […]
The Seattle Times (hat tip to ASCE SmartBrief) has reported that seven voids have been discovered above the Beacon Hill Tunnel with one opening up at the ground surface. The tunnel is being constructed by Sound Transit, the area’s transportation agency as part of a roughly $2.6 billion (yep, billion) light-rail project connecting downtown Seattle with the University of Washington and SEA-TAC airport. The voids were a result of running sand pockets in the otherwise stable clay units that were encountered by the tunnel boring machine or TBM. These voids migrated up like a chimney with one reaching the surface, almost 160-ft above the tunnel. This void was apparently 21-ft deep and opened up in a resident’s front yard and could have easily swallowed her up as she noticed it while gardening. The other voids were discovered at a depth of 20- to 65-ft below the ground surface. More after the break. (Illustration from Seattle Times)
[Updated November 17, 2009] A few new posts from Ontario-geofish [/Updated]
Those with interest in rock mechanics and tunneling might be interested in this project. The Ontario Power Generation (OPG) company is the owner of a $600M (Canadian) construction project to create a third hydro power tunnel under Niagara Falls. Apparently the project is having all kinds of problems with overbreak in some very difficult tunneling conditions which means very slow progress and big $$ overruns. (Photo from niagarafrontier.com)
I’ve been meaning to post something on this project for some time. I admit that my perspective is biased by the viewpoint you can find on the Ontario-geofish blog. I’ve mentioned Harold Asmis before, he’s the owner of the OG blog, and a former OPG employee if I understand correctly. He left OPG for a career doing geophysics and earthquake engineering for the Nuclear Power industry in Canada. I highly recommend his blog, he has great insight into tunneling, earthquakes, siting of nuclear power plants not to mention opinions on all kinds of other things. His writing style is very colorful and entertaining as well.
So, Harold has written a whole series of blog posts on the Niagra Tunnel project, including a 5-part series entitled "The Disaster of the Niagara Tunnel" and a 4-part series called "Niagara Tunnel: doing it Right". He is not directly involved with the project, but his long career with OPG and related disciplines gives him some great insights. I’ve collected a list of some of his blog posts on the Niagara Tunnel project as well as a few other links about the project. Click through for the good stuff.
City officials and residents in Amsterdam, Netherlands are looking at the recent Cologne tunnel collapse and wondering if the construction of their fourth metro line could have similar problems. Although the tunnels themselves have not […]
According to a Reuters article, Cologne State Prosecutors raided the offices of various contractors, engineers, and even the Cologne Public Transport company to collect evidence in an investigation into the cause of the collapse of […]
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)
Urban miners have been busy constructing a new water supply tunnel underneath New York City to supply the megalopolis with the water it needs. The miners, or sandhogs as they are known, are about halfway complete with the new tunnel which is expected to be in service by the year 2020. Work on the 60-mile tunnel began in 1970 and the total projected cost is $6 billion and is widely regarded as one of the most complex public works projects in the western hemisphere. When complete, it will help deliver 1.2 billion gallons DAILY to 8 million New Yorkers. The city currently gets its drinking water from two water supply tunnels that were constructed in the early 20th century and have not been inspected or repaired since then. More after the break. (Image credit History.com)
Early indications are that a collapse of a subway tunnel station still under construction was to blame for the sinkhole that destroyed Cologne’s Historical Archive, home to documents dating back to 922 A.D. More info after the break. (Photo by DPA via Spiegel Online)
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