Location:

244^th Ave NE near Redmond Fall City Rd, (SR-202). 

Issue:

In winter 2020, a slide occurred on the downhill slope of 244^th Ave NE. The slope movement caused the 90-foot-long gabion basket support wall to shift approximately two feet. This support wall, located just below the shoulder of the roadway, could no longer reliably support the edge of the roadway. A gabion basket is a steel cage box typically filled with rocks and other materials. The wall comprises approximately three baskets stacked on top of each other.

What King County did to address the issue:

• King County Road Services temporarily placed a barrier next to the damaged section of support wall and moved both travel lanes over. The barrier and lane shift were put in place as a safety precaution to help prevent the road from damage and to stop the wall from shifting further.
• Shifting both lanes over required Road Services to narrow the width of both travel lanes because the road itself is not wide enough to keep them the full width.
• Narrowing the width of both travel lanes allows this section of road to remain open in both directions until the support wall could be repaired.
• Road maintenance crews continuously monitor the road for damage, and to make sure the gabion support wall has not shifted further.
• Crews also have prioritized 244^th Ave NE to receive snow and ice pre-treatment and removal to account for the narrower lane widths.

What King County is doing to solve the issue and restore the road to full capacity:

• Road Services must fully repair the support wall to ensure it will not be compromised again.
• This type of repair requires soil samples to fully understand the underlying conditions that caused the gabion basket wall to shift. Next, Road Services engineers will use the soil sample information to design a repair plan
• As of now, the soil samples have been taken and the design team is actively engineering a plan for repairs. The soil samples have yielded data that is different than what our engineers expected. As a result, it is taking longer than usual to design the repair.
• Full repairs are expected to be complete by the end of 2022, pending any unforeseen right of way needs.

Who to contact with questions:

• Broch Bender, King County Road Services, BBender@kingcounty.gov or 206-263-1189.

 (click to enlarge)