O.C. Buildings Found Fairly Quake-Safe

Orange County buildings, particularly newer structures, probably would fare well in a massive earthquake such as the temblor that struck Northern California last week, UC Irvine engineers who inspected the damage said Thursday.

Much remains to be done, however, to strengthen or buffer buildings in areas prone to liquefaction, and the cost of such reinforcement is too high for most residential property owners, the experts said during a news conference at UCI.

Liquefaction--the churning of sandy soil during an earthquake that is likened to the action of a blender--is a threat in some coastal areas of Orange County. Damage can be lessened by compacting or draining the wet soil or adding foundation and structural braces, according to the UCI engineers.

“It’s a matter of economics, not technology,” said Roberto Villaverde, an associate professor of civil engineering. Villaverde was one of a half-dozen UCI professors and doctoral candidates who studied the collapse of the Nimitz Freeway in San Francisco and building damage throughout the region as part of an investigation by the Earthquake Engineering Institute in El Cerrito.

“If we go to the homeowner and say, ‘In order to have your house safe, you will have to spend thousands and thousands of dollars,’ and they think the chances of an earthquake are small, they will say, ‘No way,’ ” Villaverde said. “Overall, I believe that buildings here are more or less safe.”

Public and commercial buildings built in the last decade or less are likely to hold up best in a severe quake because of constantly toughened state building requirements, said Robin Shepherd, head of UCI’s reconnaissance team.

“We know of no building that failed that was in compliance with the 1982 or 1985 Uniform Building Code,” Shepherd said. “The buildings that survived best were designed to the most recent code and faithfully executed by the contractor. We can learn from the errors and omissions which have shown up in San Francisco.”

Despite more than 60 deaths and billions of dollars in damage, the devastation of Northern California was far less than the toll in a similar magnitude earthquake in Soviet Armenia a year ago. Shepherd said higher construction standards and greater preparedness helped the densely populated San Francisco region escape massive casualties.

“It’s a success story for structural engineers,” he said. “We are providing a higher level of seismic safety for less money.”