Second Issue of International Journal of Geoengineering Case Histories [Official This Time]
Project Related
Voids Open as a Result of Tunneling Under Seattle’s Beacon Hill
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)
Comings and Goings
Geocomp Corporation Celebrates 30 years!
Congratulations to Geocomp Corporation on their 30 year anniversary. Geocomp provides design & consulting, instrumentation and monitoring, lab testing equipment and products, and high-end lab testing services to the geotechnical industry. Find out more about […]
Project Related
Backfilling the 1931 Tucker Tunnel in St. Louis with Geotechnical Fill, Geofoam Blocks
Constructed in 1931 by the Illinois Terminal Railroad, the Tucker Tunnel is located underneath Terminal Boulevard in downtown St. Louis. Over the years, the tunnel condition has deteriorated and the concern is that the failure […]