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228 bridges at top of state list for fixes

Among them are the Santa Monica Freeway viaduct, 5/10/101 split and 5/60 interchange. Caltrans says they pose no danger of collapse.

August 13, 2007|Ari B. Bloomekatz | Times Staff Writer

Although Caltrans insists that the thousands of bridges it maintains are safe, the agency has identified 228 spans that officials say should be at the top of the list for repairs.

Officials said these bridges pose no danger of collapse but are considered top priorities for fixes based on such factors as structural problems and how much they are used by cars and trucks.

Those on the list received a "sufficiency rating" by inspectors of lower than 50 -- based on a possible top score of 100. Each bridge's score was calculated by weighing various factors such as structural adequacy and safety, which accounted for 55% of the rating. Other factors include how heavily traveled the spans are.

Of the 228 bridges listed on the "Priority Structurally Deficient Bridge List," 17 are in Los Angeles County. They include the interchange of the 5 and 60 freeways in Boyle Heights, the 5/10/101 split in downtown Los Angeles, the Commodore Schuyler F. Heim lift bridge near Terminal Island in Long Beach and the Santa Monica Freeway viaduct in downtown L.A.

The announcement comes in the wake of the collapse of the Interstate 35W bridge in Minneapolis that prompted transportation officials and engineers across the country to reinspect their own bridges and rush to guarantee their safety.

Mark DeSio, deputy director of external affairs for the California Department of Transportation, said the agency has reinspected all of the bridges similar to the Interstate 35W bridge, and engineering experts said the types of environmental and structural problems that faced the Minnesota bridge are starkly different from the problems facing spans in California.

Caltrans, which operates more than 2,000 bridges in Los Angeles County alone, said its bridges throughout the state are safe to drive on. The targeted bridges are those used the most and that need the most help, officials said. "If a bridge was deemed not to be safe, it would be immediately closed until it was repaired," DeSio said.

Federal officials have classified thousands of bridges throughout California as being "structurally deficient" -- but local officials stressed that that did not mean the spans were in any danger of falling down like the one in Minneapolis.

In fact, California might be in better shape than other parts of the country because bridges here are already designed to withstand earthquakes.

"The biggest threat to bridge safety would be earthquakes," said Thomas Sabol, professor of civil and environmental engineering at UCLA.

"Unlike many other parts of the country, where the environmental threat might be corrosion caused by road salts put down on the bridges during the winter, most bridges in California are not subjected to that kind of abuse."

Sabol said spans throughout the state also can be worn down by increasing truck payloads, corrosion caused by flooding and bridge fatigue -- a condition he explained by comparing an aluminum can that was twisted back and forth repeatedly and would eventually rip.

"That happens on an extreme scale to bridges," Sabol said.

Mike Kincaid, co-chairman of the California Infrastructure Report Card for the American Society of Civil Engineers, said bridges on a whole throughout the state were "average." The society scored Los Angeles County bridges with a grade of C.

"There's a need out there, but that doesn't mean we expect things to fall down any time soon," Kincaid said. "I think it'd be very unusual to see a bridge have a serious problem like that one did out east."

Caltrans identified the 228 most troubled bridges through a rating system.

A sufficiency rating score of 0 is the lowest, ranging up to 100, but Caltrans officials stressed that low numbers do not mean a bridge is unsafe.

If the score is below 50 and a bridge is given the status of structurally deficient or functionally obsolete, it is eligible for federal funding.

DeSio said those terms can be misleading.

"The terms 'structural deficiency' and 'functionally obsolete' are simply used as a measure to establish eligibility for funding for bridge repairs or replacement," he said.

Kincaid said federal funding is critical because the state lacks the resources to complete repairs on all of its bridges.

The report card suggests spending about $5.3 billion on bridges within Los Angeles County and billions more each year on transportation and bridges throughout the state, amounts of money that Kincaid concedes may not immediately be within politicians' reach.

"The longer we let that sit because we do not have the money to allocate to it, we're really increasing that cost by a factor of five," Kincaid said. "We should not have to have a loss of life to make improvements to the infrastructure."

In addition to the 228-bridge priority list, Caltrans has 1,620 bridges classified as "structurally deficient."

A list also has been released of state highway bridges that are "fracture critical," referring to a steel structure that does not allow the bridge to redistribute its load to other sections of the span if it breaks.

Los Angeles County has 18 such spans, including the landmark Vincent Thomas bridge, the Heim bridge and the Santa Monica viaduct.

The American Society of Civil Engineers warns that there is a 65% chance of an earthquake measuring 6.7 magnitude striking California by 2030, and that officials need to be sure bridges can withstand the impact.

ari.bloomekatz@latimes.com

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