Managing Agency: City of Portland Primary Contractor: Cascade Bridge, LLC Primary Consultant: City of Portland, Bureau of Transportation (PBOT) Nominated by: Oregon APWA Classification: Less than $5 Million Category: Historic Restoration/Preservation
As the oldest intact bridge in Oregon, the NW Thurman Street Bridge was in critical need of modernization and rehabilitation. Wooden sidewalks caused many pedestrians to trip and slip during the wet Portland winters. Structural deck elements like wood stringers and deteriorating steel floor beams caused many potholes and cracks along the bridge deck surface. Furthermore, TriMet buses were forced to reduce their speed while crossing the bridge due to weight restrictions and significant shaking. Fire trucks were forced to make a 1 mile detour because of the weight restrictions. The NW Thurman Street Bridge Rehabilitation project goals were to:
Replace the critically deteriorated riveted steel and wood superstructure with new material capable of withstanding asphalt roads.
Lift the weight restriction by replacing the wood stringers and old floor beams with new steel elements. Corrugated steel deck panels were installed for the placement of the wearing surface.
Restore the historic significance by replacing the chain link fence installed in 1955 with a replication of the 1905 decorative pedestrian railing. The new railing was designed by referencing the 1905 shop drawings.
Provide safer pedestrian access by replacing the wooden sidewalk with textured aluminum planks.
More information is available on this project by going to the following links: