The Butte City Bridge project on State Route 162 in California is nearing completion after replacements due to an aging structure, and environmental challenges. The funding from federal and state sources totals $114 million. Project completion is set for 2026.
Caltrans photo
Builders construct falsework for a span of the new bridge over the Sacramento River.
The ribbon cutting for the Butte City Bridge and Viaduct on State Route 162 in Butte City was June 3, 2025, but 3,100 vehicles, including 400 trucks, have traversed the structure since the winter, following a bridge replacement project.
The contractor, Golden State Bridge Inc., replaced the existing steel bridge built in 1948 with the new 4,686-ft. span, which has standard 12-ft. traffic lanes and 8-ft. shoulders.
The bridge, whose official name is the Sacramento River Bridge, opened before the ribbon cutting because there was movement in the pillars on the old bridge from debris in the river.
The old bridge had reached its lifespan, according to Megan Reese, a California Department of Transportation (Caltrans) spokesperson, and it wasn't up to standards. The old bridge had sustained damage, there were misaligned piles and the bridge needed to be widened.
"Instead of throwing all of our money into an older bridge, it was cost effective in the long run to build a new bridge," Reese said.
"This project will preserve and extend the useful life of the existing roadway throughout the project limits and replace the existing Sacramento River Bridge and viaduct to meet current design standards," she said.
Primary subcontractors on the project, which began in March 2022, included the rebar replacement company, Commercial Metals Co., also known as CMC, based in Texas, and the California-based earthworks subcontractor, Teichert Construction.
Caltrans photo
As with any structure, the project began with the foundation, said Matt Crete, a Caltrans transportation engineer. That was followed by excavation and reinforced concrete placement. After the foundations were complete, he said the columns were built on piers; each pier had two columns.
After the columns were built, the bridge's superstructure was built with reinforced concrete girders and bent caps, which transmit loads from the superstructure into the columns and foundations.
The last section to be completed was the bridge's deck. For the last few years, Caltrans has used micro and macro fibers in the concrete as well as shrinkage-reducing admixture.
The fibers, Crete said, offer greater tensile capacity in the concrete and help prevent the concrete from cracking when it dries out and, in general, improves the quality of the concrete. The admixture gets mixed into every yard of deck concrete and helps prevent the concrete from shrinking and reducing in volume as it dries.
Caltrans has used shrinkage-reducing admixtures on statewide projects consistently for six or seven years, Crete said.
"It extends the life and improves the quality of the bridge and reduces the overall lifecycle maintenance cost of the bridge," he said.
The approach and departure roadway sections were built and graded intermittently, especially toward the end of the project. The final paving will be during the summer or fall.
"The demands from the traffic design require a depth of asphalt to be put down that is unmanageable and ends up being an inferior product if you put it down in a single lift," Crete said. "There has to be multiple applications of asphalt put down."
The project required two 300-ton cranes and one 250-ton crane; excavators, arial manlifts, diesel impact hammers, hydraulic rams, mobile forklifts and welders — both personnel and equipment.
For much of the project, there were three dozen workers on the site daily, Crete said.
Caltrans photo
The project faced environmental and weather challenges.
"For three successive winters, for the life of the project, we've had some pretty significant rains and we've had job sites flooding, either localized or across the entire flood plain, and that's caused pretty significant damage to our temporary access trestles and some of the temporary structures that have supported the bridge while the concrete was curing before it was actually able to support itself," Crete said. "Those impacts and those damages had to be repaired."
This meant that the contractor had to build "much more robust driven pile foundations for the temporary structures for the new bridge over the river." Because of the storm damage and the limited access, for the last few months of the project the contractor used barges for more efficient access to the portions of the structure over the river, Crete said.
"Overall, that hasn't really had significant impact on the schedule, but that's been a huge reflection on the efforts and the commitment by Caltrans and the contractor to really work things out and resolve issues quickly and in the best interests of everyone involved," he said.
Additionally, the project had limited work windows in the river due to restrictions placed by the Environmental Access Permits.
Some of the native species that inhabit that part of the river are on the endangered species list, while others are threatened and others are protected.
"Based on their reproductive cycles, we're only allowed certain months of the year that we can actually work in the water to try to limit the threat we pose to those species," Crete said.
One advantage that the project had was that the old bridge was in operation during construction.
"We didn't have the inefficacies that normally come with maintaining public traffic when you're under construction," Crete said.
Caltrans photo
The project cost was $114 million and was funded by federal and state sources.
Specifically, it was funded under the 20.XX.201.113 State Highway Operation and Protection Program (SHOPP), which is eligible for federal aid. SHOPP funding is a combination of state fuel taxes, federal funding, and SB 1's Road Maintenance and Rehabilitation Account (RMRA).
In addition, the project received federal funding through the Highway Bridge Replacement and Rehabilitation (HBRR-S) program, which is supported by the Federal Highway Trust Fund. The Trust Fund itself is primarily financed through federal excise taxes on motor fuel.
Crete said Golden State Bridge Inc. plans to reuse as much as possible the materials they used to build the temporary structures.
The entire project will not be completed until 2026 with the demolition of the old bridge. CEG
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