Crews Complete Work on SW Admiral Way Sinkhole

On August 26, a sinkhole — also known as a void — opened up in the 5300 block of SW Admiral Way.

Neighbors in the immediate vicinity reported that at 1 p.m. there was no void but by late afternoon, a significant hole in the pavement had rapidly opened up. 

An SDOT Response Team Truck at the area of the sinkhole placed traffic cones to direct traffic safely.
Traffic was diverted while crews began making emergency repairs | Photo credit: Patricia Westsik

Our SDOT Response Team (SRT) quickly secured the area, placing cones and diverting traffic while a temporary cold patch mix was applied, and then a temporary steel plate was installed, allowing the travel lanes to be reopened in their existing location — without having to merge the motor vehicles with the bicycles — to ensure the safety of the road.

Crews work to install a steel plate over the sinkhole. Image includes a backhoe, people, and traffic cones around the repair area.
Crews install a temporary metal plate over the void | Photo credit: Ken Ewalt

Following these initial temporary repairs of SW Admiral Way, we collaborated with Seattle Public Utilities (SPU) to try to diagnose the cause of the sinkhole. SPU ran a CCTV camera through the sewer pipe but did not find any  structural issues with the pipe.  SDOT and SPU staff coordinated efforts to make this happen relatively quickly. 

After the diagnostic work was complete, SDOT crews efficiently filled the void and also restored two nearby utility cuts (within 150’ of the location of the void)  at the same time. By doing this, they avoided having to coming out twice, which minimized the impact to the local community.

Finished asphalt paving over the area where the sinkhole had been.
The original location of the sinkhole, with paving completed | Photo credit: Paulino Pablo 

The cause of sinkholes can be difficult to diagnose and we will continue monitoring this area as necessary. 

We’re grateful to our SDOT Response Team, Asphalt Paving, and Concrete Paving staff for their outstanding work on this project!