OBEC worked closely with the ODOT Bridge Preservation Unit on the design for the $10.6 million rehabilitation of this historic arch bridge, originally designed by the famed Conde B. McCullough and constructed in 1922. The bridge connects Oregon City and West Linn across the Willamette River and serves as a valuable transportation resource.
Though the 755-foot-long bridge appears to be a concrete structure, it is actually entirely comprised of structural steel covered with shotcrete, cast-in-place concrete, and other coatings. It is the only bridge in Oregon to be encased in gunite, originally meant to protect it from corrosion due to the sulfur dioxide emissions from paper mills south of the bridge.
Leaking expansion joints caused deterioration of the supporting elements and general weathering of the concrete portions of the bridge has left several cracks and spalls. The weakened structure requires extensive rehabilitation including deck overlay, floor beam end and hanger concrete replacement, arch chamber bottom slab replacement, sidewalk and rail replacement, pylon and replica luminaire replacements, shotcrete removal on arch ribs and other structural steel, and specific detail and structural work. The rails will be designed to retain their historic charm.