How Caltrans raised seven Placer County freeway bridges
After a year of heavy lifting, California highway officials are nearly done with an improbable task on Interstate 80 in Placer County: raising seven freeway overcrossings between Loomis and Weimar, in some cases by more than 2 feet.
The $36 million “Raise 80” project has involved jacking up and repositioning 1,000-plus ton overpasses, many of them a half-century old, to comply with federal 16-foot-6-inch standards so modern supersized trucks and military vehicles can squeeze under them.
State Department of Transportation spokeswoman Liza Whitmore said completing the project has taken a combination of brute strength and intricate choreography.
“It’s quite the engineering marvel,” she said at the Newcastle Road overpass last week. “A huge endeavor.”
For years, taller trucks had to exit the freeway and wind extra miles along Placer County roads to avoid a run-in with an overpass that was too low. Several overpasses show scrapes and gouges from incidents over the years.
The project represents, in a sense, finishing work for a larger modernization program on the highway that winds through the mountains and connects California commerce to the rest of the United States. In 2013, Caltrans concluded a decadelong $820 million redo of the freeway, rebuilding many sections from scratch between Auburn and the Nevada state line.
Those renovations accommodate an estimated 170,000 commercial trucks and other travelers daily. An estimated $4.7 million worth of consumer goods crosses the summit each hour, making it one of the busiest commercial corridors in the country.
The final overpass lift took place two weeks ago in Newcastle, where the bridge spans 74 yards from end to end and weighs 1,250 tons. That bridge, built in 1959, was 14 feet 9 inches tall, far less than federal minimums for vertical clearance. Caltrans officials said the lowest corner of the bridge had been hit so many times over the years that rebar was showing.
Crews used jackhammers to slice the bridge on both sides at its abutments, essentially cutting it free from its mooring on either side of the freeway. They bolstered it underneath with steel beams and cut the supporting columns in half, essentially leaving the structure hanging in space, held up by the temporary beams. The project contractor was RGW Inc. of Livermore.
The actual lifting of the bridge took one night and required 20 hydraulic jacks. One crew member worked a master panel, pumping small amounts of oil into each jack, lifting each by tiny increments. Workers with tape measures at each jack shouted out the fractions of inches.
“They are yelling out, ‘three-quarter, three quarter, I have five-eighths, five-eighths,’ ” Whitmore said. “All of them have to be in sync so that the overcrossing doesn’t tilt.”
The columns beneath the bridge were rebuilt, filling in the gap the lift caused. The streets leading up to the overcrossing have been raised and rebuilt as part of the project, and new sidewalks have been installed. Over time, new guardrails will be installed.
Newcastle Road, currently closed at the site, is scheduled to reopen Thursday.
The state has one more overpass to take care of: the Union Pacific railroad bridge at Newcastle. In that case, because the overcrossing is privately owned by the railroad, Caltrans will close the freeway in early May and lower the road surface beneath the crossing.
In one other instance, at the Weimar crossing, Caltrans lowered the freeway road surface rather than raising the bridge because only a portion of that bridge was too low.
The work began in September 2014 and is expected to conclude by the end of June. Other overpasses east and west of the project site are newer and taller, and did not have to be lifted to meet federal standards, Whitmore said.
The I-80 freeway was built between 1957 and 1964 as part of the Federal Highway Act. Crews finished the first portion from Sacramento to Truckee in the late 1950s, in time for the 1960 Winter Olympics at Squaw Valley, so fans wouldn’t have to slog single-file up old Highway 40.