The Colorado Department of Transportation and contractor SEMA Construction have installed the new Dolores River Bridge on Colorado Highway 90, according to a CDOT news release.
The precast concrete bridge, about four miles east of Bedrock and 15 miles east of the Utah-Colorado state line, provides wider and higher clearance for oversized vehicles, replacing a truss bridge with limited clearance. The new bridge cost about $3.8 million, including design and construction, CDOT said.
“The project team was faced with some unique challenges including dealing with an historical structure, meticulously dismantling it, and keeping track of the steel beam pieces,” said Andrea Meduna, senior project engineer.
In addition to managing automobile traffic during construction, crews also encountered unusual traffic below the bridge, CDOT said. While motorists may typically encounter a cone-zone on the roadway, rafters and boaters met “buoy zone” at the site.
“The high country snowpack resulted in very favorable spring rafting conditions for our river friends,” Meduna said. “To accommodate the rare occurrence of being able to raft this section of the Dolores, we developed a river use plan which assisted safe floating through our construction zone.”
The bridge was targeted for replacement in fall 2014, when a crack was discovered in a beam of the original steel truss bridge. The damage forced the closure of the old bridge, and a temporary bridge was constructed to allow single-lane, alternating traffic.
The old Dolores River bridge was a steel Pennsylvania through-truss bridge built in 1952. In 2002, the bridge was listed on the National Register of Historic Places for its architectural significance. The Dolores River Bridge was one of 10 remaining intact steel through-truss bridges in Colorado. It was dismantled piece by piece, labeled and stored in a CDOT facility for possible use as a pedestrian or bike structure.