The Washington State Department of Transportation is following through on several actions in response to the tragic Minnesota bridge collapse.
On Aug. 3, U.S. Secretary of Transportation Mary E. Peters advised all state transportation agencies to re-inspect all steel deck truss bridges with “fracture critical” members. Steel deck truss bridges are similar to the bridge that collapsed in Minnesota (definition: “fracture critical” refers to a bridge component that might cause the entire bridge to collapse if that component failed).
At a minimum, the U.S. Department of Transportation recommended that states review inspection reports for steel bridges with fracture critical members to determine if more detailed inspections are warranted.
Interim Transportation Secretary Paula Hammond on Aug. 3 directed WSDOT engineers to follow the federal advice to conduct a review of steel deck truss bridges.
There are 45 steel deck truss bridges in Washington – 26 owned by WSDOT and 19 owned by local cities and counties (note: this number was updated Aug. 8, 2007). All 45 of these bridges were inspected within the past two years. Of the 26 state owned steel deck truss bridges, 10 were inspected in the past six months and three more are slated for inspection this fall.
Over the next few weeks, engineers will review all inspection records on those steel deck truss bridges that are also determined to be structurally deficient (roughly 6 of the 45) to determine whether additional in-the-field inspections are warranted. Structurally deficient bridges are safe to drive on but have components that require repair or replacement.
Engineers have labeled 363 bridges of all types in Washington as structurally deficient. In addition to USDOT’s recommendation of review of steel deck truss bridges, WSDOT bridge engineers will next re-examine inspection reports on the remaining steel bridges currently on the structurally deficient list that have fracture critical members (60 of the 363 structurally deficient bridges).
We have absolute confidence in WSDOT’s professional engineering staff and standards. Our inspection teams are educated about and use the most up-to-date bridge inspection techniques available.