Earthquake: The Long Road Back : 8 County Bridges Reinforced for Quake Safety, Caltrans Reports : Transportation: Eight other structures are under reconstruction and 18 more will be retrofitted as part of the ongoing fortification program, according to officials.

Eight of Ventura County’s 322 elevated highway sections have been recently reinforced to withstand the impact of a major earthquake, with eight more bridges currently under reconstruction and 18 others slated for retrofitting, Caltrans officials said Friday.

“What we have done is we have inventoried, examined and considered every bridge in Ventura County,” California Department of Transportation spokesman Jim Drago said of the ongoing fortification program.

“These are the ones that were determined to be candidates for retrofitting,” Drago said. “The list is dynamic. . . . There could be bridges added, particularly in a case like this earthquake, where there was some new seismic activity discovered, i.e. a new fault.”

Meanwhile, Caltrans officials said Friday they had completed preliminary and follow-up inspections of all bridges and freeway overpasses in Ventura County in the wake of Monday’s quake and subsequent aftershocks and proclaimed all open and safe to travel.

“I don’t foresee any problems on the freeways and I haven’t heard of any,” said Bob Houle, an associate transportation engineer. “Everything’s open and functioning.”

In the program for seismic reinforcements, Drago said determining exactly which bridges need shoring up depends on several factors.

“We identify bridges which we consider candidates for retrofitting. What happens then is that a team of Caltrans engineers are given the job of examining the bridge in detail,” Drago said.

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“They determine the forces that could be generated by the maximum credible earthquake that could hit that site,” Drago said. “They then track those forces through the bridge to see what happens to those forces when they would strike the bridge and they develop a strengthening technique.”

Caltrans launched a major program to inspect overpasses, bridges and highway interchanges after the 1989 Loma Prieta earthquake, when a double-decked segment of the Nimitz Freeway collapsed onto a stream of rush-hour traffic in Oakland, sending the quake’s death toll soaring.

The bridges that have been retrofitted in Ventura County are:

* Ash Street pedestrian crossing over the Ventura Freeway.

* Chestnut Street overhead bridge at the Ventura Freeway.

* Padre Juan Canyon bridge on the Ventura Freeway.

* Hill Road pedestrian crossing over California 126.

* Laurie Lane bridge at California 126.

* El Rio underpass on Pacific Coast Highway.

* Olsen Road overpass on California 23.

* Casitas Vista Road on California 33.

The retrofitting work often involves digging around the footing of a bridge and adding steel and additional concrete. Bridge decks are also hooked with cables that would keep them from falling to the ground in the case of an earthquake.

Highway workers were out on the Simi Valley Freeway again Friday, grinding down or repaving buckled portions of the ramps leading to the freeway from surface streets in the city’s hard-hit east end.

The county’s freeway system generally fared well through Monday’s quake and aftershocks that continued through Friday, said Dave Servaes, Caltrans’ regional manager for Ventura County.

One freeway overpass was briefly closed about 2 p.m. Wednesday after drivers reported cracks in the Sunset Hills Boulevard bridge that passes over California 23 in Thousand Oaks. A Caltrans inspector investigating the complaint determined that the chipping was superficial and that the overpass was safe.

“Every time we have an aftershock, we get deluged with phone calls that the bridges are falling down and we go look again and it’s the same thing we found before,” Servaes said.

“We’re not having to shore up anything,” Servaes said. “We’ve had some problems with the approaches and departures on a couple of the bridges that we’re working on right now.

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“There are not as many bridges and they’re not as big (as in Los Angeles County),” he said. “The big bridges that we have out here, like the 118 and the 23 (the Moorpark-Simi Valley freeway connector), that’s a huge, long one but it’s built with the latest technology and it came through it OK, and that’s not because it didn’t shake--I can tell you that.”