Damage to Chamber Way Overpass Estimated at $6 Million; Temporary Bridge Planned

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Drivers irked by the loss of the Chamber Way overpass this week may not have to wait long to cross the busy intersection again.

Washington State Department of Transportation staff announced Thursday that a temporary steel bridge could be in place over the removed south span of the overpass, in as little as two weeks.

Bart Gernhart, assistant regional administrator for engineering for WSDOT’s Southwest Region, said at a meeting with the Chehalis City Council Thursday that he hoped crews could begin construction on the bridge as early as Friday afternoon.

“Early next week, we’ll have a better idea of where we’re at,” he said.

Governor Jay Inslee declared a state of emergency regarding the bridge this week, citing the estimated $6 million in damage to the structure. The state is negotiating with the insurance company of the driver of the oversized load that struck the bridge to cover the cost. 

Chehalis Mayor Dennis Dawes thanked the WSDOT and state representatives for their work on the issue.

“This has been going on non-stop since this incident occurred,” he said.

At about 11:45 a.m. on Friday, an oversize load of two excavators towed by a southbound 2005 Freightliner semi truck hit the underside of the overpass, scraping baseball-sized chunks of concrete onto two passing cars, according to the Washington State Patrol.

The driver of the semi, identified by the State Patrol as Henry Abadia, 35, of Las Vegas, Nevada, was cited for having a load that was too tall. The crash was caused by inattention, according to the WSP.

Gernhart said the WSDOT’s top two priorities in the past week have been safety and getting people over Chamber Way again as quickly as possible.

“The night it was hit, we chipped the loose concrete and pulled the loose rebar off,’ he said.

The WSDOT immediately closed the bridge to traffic after the collision and brought in engineers to survey the damage.

While the bridge seemed to be structurally sound under its own weight, four of the six girders supporting the bridge deck’s weight were damaged beyond repair, Gernhart said. Some of the girders showed signs of previous repairs from collisions, he said, and engineers worried about what would happen if it got hit again.

“It looks like there was a good chance for that to come crashing down,” Gernhart said.

According to state data, the Chamber Way overpass has been hit by oversize loads nine times in the past 10 years.

With that concern in mind, the WSDOT secured an emergency contract and crews tore down the damaged span over southbound I-5 Tuesday night.

During a brief public comment period at Thursday’s meeting, Ron Averill asked why the state didn’t have a better system for stopping oversize loads before they hit overpasses.

“We seem not to have an adequate emergency management system,” he said.

Gernhart explained that some overpasses have radar warnings for truck drivers with oversize loads, but said they tend to be ineffective because they are too sensitive, and are often set off as often by low-flying birds as oversize trucks.

With the damaged third-span of the bridge deck removed, and the safety concern taken care of, WSDOT staff began brainstorming about their options for quickly getting traffic over the freeway at exit 79 again.

“We identified at least a dozen different options,” Gernhart said.

Rebuilding the concrete bridge deck could have taken more than a year, he said. The state Legislature has set aside $75 million to redo the Chamber Way Overpass and accompanying on and off ramps in preparation for the future addition of two lanes to I-5, Gernhart said, but funding for the design on the project isn’t authorized until at least 2019, with construction coming as late as 2023.

State Rep. Ed. Orcutt, R-Kalama, and state Sen. John Braun, R-Centralia, told The Chronicle this week that they were looking into the possibility of moving the project forward.

WSDOT staff decided to focus on quicker, more feasible options in the short-term, but first had to create a computer model of the bridge, which was built in 1958.

“We don’t have a good model of the bridge,” Gernhart said. “That’s critical to have.”

The computer model helps engineers calculate how the bridge will react to different weight loads and other situations, he said. After that model was developed, staff could once again begin to discuss short-term options.

Staff eventually decided that the best short-term option is to install a steel Acrow Bridge. The Acrow corporation has a location at the Port of Centralia.

“They’ve worked non-stop with us,” Gernhart said. “Without them, we wouldn’t be able to open this in a couple weeks.”

The bridge can be installed in pieces, and is strong enough to handle any type of vehicle legal on the freeway, Gernhart said. Oversize loads would not be permitted over the Acrow Bridge.

The only hitch, Gernhart said, is the bridges come in 50-foot increments, and the span that was removed was 51 feet, 6 inches, so crews will need to retrofit the existing bridge to cover the extra foot and a half, and to account for the fact that the old bridge has six girders, and the Acrow Bridge has two.

“The challenge is how do they fit, how do they match up with our crossbeams?” Gernhart said.

The Acrow Bridge deck will also sit several inches higher than the existing roadway on the bridge, and engineers will have to build ramps for traffic.

“We haven’t designed it completely yet,” Gernhart said.

Engineers are also trying to find a way to use existing bolts on the overpass to connect the temporary structure.

“We don’t know if they’ll come off,” Gernhart said. “They’ve been there since 1958.”

WSDOT staff plan to bolt the Acrow Bridge to the existing overpass.

The temporary structure will also have a much higher clearance than the demolished bridge section. Chamber Way is marked at 14 feet, 8 inches, but the Acrow Bridge will be 16 feet above the road, the Federal standard for freeway overpasses, Gernhart said.

In the meantime, the WSDOT plans to add additional signage to direct drivers away from the overpass.