Seattle’s Alaskan Way Viaduct and Seawall Replacement Project is a political lightning rod, but this amazing simulation video released by WSDOT underscores what COULD happen if a significant earthquake struck the Seattle Downtown Waterfront area.
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)
Available Resources
Micropile & Anchored Earth Retention Safety Video
The ADSC/IAFD has produced a safety video on Micropile & Anchored Earth Retention. It’s sure to be a great training video for contractors, but it is also a great resource for engineers and inspectors who […]
Geologic Hazards
Alaskan megathrust fault more active under Kodiak
The 1964 Alaska Earthquake was 9.2 in magnitude and caused dramatic destruction and dramatic examples of surface rupture, subsidence, and liquefaction. New paleoseismic evidence points to a previously unknown earthquake that happened on the same […]