The new Hamilton Branch Bridge on Highway 147 is nearing completion after a delay of at least two months, due to inclement weather earlier in the year that produced a large amount of runoff, causing a late start on foundation work, explained Jim Rogers, Caltrans construction project senior engineer.
“Because of unforeseen circumstances, the contractor was delayed at the start of the construction project after heavier than expected rains in the winter raised the stream to a higher level than projected,” he said. “The contractor had to modify his original plans before demolition could begin on the old bridge, and construction on the new bridge could proceed.”
The completion date has been rescheduled from the beginning of November to around Christmas, Rogers estimated. “We’re hoping to open the new bridge to traffic no later than by the end of the year,” but the exact date will depend on how weather conditions affect construction work.
Viking Construction of Sacramento was awarded the contract for the new bridge through funds that were available from the California Department of Transportation’s 2012 State Highway Operation Protection Program, with construction on the bridge getting underway April 3.
The subcontractor is Stimpel-Wiebelhaus Associates of Redding, providing excavation work.
The bridge is located near the town of Clear Creek, 1.5 miles east on Highway 147, and serves as a bypass to connect State Route 89 on the eastern side of Lake Almanor and State Route 36 north.
Bridges usually have a 60-year life before major repairs or replacement is needed, noted Lupita Franco, Caltrans District 2 public information officer. She said that a large number of California bridges were built in the ‘40s through the ‘60s, “and many are in need of repair or replacement.”
Before a permit was provided for construction, “We had to be in compliance with environmental regulations dictated by federal and state law. … It’s a long process that can take years to complete.” The planning stage for replacement of the Hamilton Branch Bridge began in 2015.
Caltrans District 2 is responsible for more than 1,700 bridges over 27,307 square miles, encompassing Lassen, Plumas, Modoc, Shasta, Siskiyou, Tehama and parts of Trinity and Butte counties, and currently has nearly 120 projects in various stages of development.
According to Caltrans initiation documents: “The purpose of this project [Hamilton Branch] is to provide a structure that meets modern highway design standards. … The [old] bridge had several deficiencies related to width, bridge rail and other issues in the deck. Significant structural work was needed to eliminate substandard conditions. The need for bridge replacement is also based on seismic concerns and to provide best value to the traveling public.”
The old 24-foot wide bridge, built in 1948, was too narrow and didn’t provide shoulders for pedestrians or bicyclists to cross safely, Rogers said. In other words “it didn’t meet modern standards.”
The new bridge, at a cost of around $6.3 million, is a cast-in-place concrete boxed girder reinforced with steel rebar, he said, and will have two 12-foot lanes, plus an eight-foot shoulder on each side of the structure for foot traffic. It’s slightly longer than the old bridge at 352 feet. The concrete deck was poured Nov. 18.
“We’re aware that residents are anxious to have the bridge opened as soon as possible,” Rogers said, “and we’re doing our best to see that happen.”