Map shows settlement on Seattle’s waterfront

A newly released map shows the extent of ground settling around Seattle’s Pioneer Square.

The Washington State Department of Transportation said its crews, along with Seattle Tunnel Partners, are continuing to survey the Alaskan Way Viaduct and areas around it determine if there’s ongoing settlement.

The WSDOT announced last week that it detected about an inch of settlement near the pit that is being dug so workers can access Bertha, the tunneling machine, for repairs. While WSDOT spokesperson Todd Trepanier didn’t blame the drilling, he did say the settlement coincided with the same timeframe that crews began de-watering the pit.

WSDOT’s map is a visual representation of the survey results shared on Dec. 5 that indicate about 1.4 inches of settlement in some areas. WSDOT said it does not make conclusions about the effects of de-watering for the access pit.

The epicenter of the settlement appears to be where Cowgirls Inc. is located.

WSDOT said inspectors are taking twice daily measurements at the bottom of both the east and west columns of the viaduct and measurements of deep survey points (80 feet below ground) about every other day.

In addition to inspecting nearby buildings that have also settled, crews are also surveying sidewalks and streets from Alaskan Way to Second Avenue and from Yesler Way to South King Street twice daily.