Less traffic in Kenmore despite bridge closure
Dec 19, 2018, 10:17 AM
Avenue in Kenmore, just before the bridge over the Sammamish River. (City of Kenmore)
(City of Kenmore)
The 68th Avenue Bridge in Kenmore remained closed through Wednesday morning after a construction mishap created a sinkhole under the south approach to the bridge on Monday night.
The congestion was much better Wednesday than on Tuesday morning, when the closure caught the 26,000 vehicles a day that use the bridge off-guard. There were hours-long delays on 522 and on many neighborhood streets. The bridge crosses the Sammamish River, connecting Kenmore and the north end of Juanita.
The Northshore Utility District is moving the sewer lines just south of the bridge span. They didn’t want to cut open the road, which would have forced its closure. Utility District engineer Dave Kaiser said they instead decided to tunnel under the road.
“We over-mined, is the term we would use,” Kaiser said. “We took out more material than we intended to, and the resulting void worked its way up to the surface and created a sinkhole.”
That void was 20-by-20 feet across and 6-feet deep. Fortunately, the concrete above did not collapse into the void. It sank a bit, more of a depression than a hole, Kaiser said. Workers have been filling the void from above, pouring concrete in from drilled holes.
Crews still have to do some road repair work before they can re-open 68th Avenue and re-connect Kenmore with north Juanita and Finn Hill.
The Northshore Utility District is moving the sewer line in preparation for next year’s project to replace the 68th Avenue Bridge, which has been weight-restricted for years. There are currently two spans, one in each direction. The southbound bridge — to be replaced — is the original span, which was built in the 1930s. Lanes in both directions are expected to remain open during the years-long project.
