A nifty BIM-type view of the proposed bored tunnel for Washington SR 99, the tunnel to replace the aging Alaskan Way Viaduct along Seattle’s waterfront. It’s pretty neat to see the piles and foundations for other structures and major utilities as the bore passes by them. A little on the longer size, at around 5 minutes.
GeoPrac.net sponsor Novo Tech Software recently released this video that gives an overview of their company and all of their various geotechnical software products. Very impressive, check it out! Related
The Port Authority of Allegheny County (Pittsburgh, Pennsylvania) has a major transit improvement project dubbed the North Shore Connector. Its main components are twin bored tunnels 1.2 miles long that will connect the Port Authorityâ€™s Light Rail Transit system, the T, 1.2 miles from the Gateway Subway Station underneath Stanwix Street and the Allegheny River to the North Shore. It will travel under the river and provide three new stations and allow for future improvements beneficial to future development and continued downtown revitalization. The $435 million project is making news recently for cost increases, drawing comparisons to Bostonâ€™s Big Dig much to the dismay of the Port Authority. Read on for project maps, links and more info.
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)