WSDOT will allow only one opening per day of the drawbridge to marine traffic.
WSDOT closed the bridge to motorists Aug. 5 after noticing unusual movement on the bridge and then discovering severe erosion and degradation of the timber piles that support the bridge’s concrete piers.
Short-term temporary repairs will help stabilize the bridge but will not provide enough support to open the bridge to vehicular traffic. This work involves tying the bridge back with steel cables to support the easterly pier.
Engineers have already started designing more permanent repairs for the bridge, which will allow it to reopen to vehicles. The design effort is expected to take at least three weeks before construction can get under way. The best estimate now is that the permanent repairs will be completed by sometime in November, although after the bridge reopens to vehicles, additional ongoing work will occur over the next year to fully implement the repairs. No traffic impacts are expected as this additional work is completed.
Dayton said crews will begin on Wednesday to use suction pumps to remove 600 cubic yards of mud and sediment – enough to fill 60 dump trucks – from inside the unstable, hollow concrete pier. This slow and tedious process was made more complicated when test samples showed lead contamination in the mud. This requires specific handling and disposal, and crews are moving as quickly as they can while making sure safety and environmental standards are met.
Removing sediment from inside the pier is necessary to reduce the load on the timber piles. Sediment builds up over time within the pier due to tide action.
Built in 1927, the Simpson Avenue Bridge is a 1,978-foot-long bridge that spans the Hoquiam River and carries 15,000 vehicles a day.
For more information, visit: www.wsdot.wa.gov/Projects/US101/SimpsonBridgePierRepair/.