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Quake Adds to Agenda for Structural Engineers

October 12, 1987|GEORGE STEIN | Times Staff Writer

CORONADO — For California's structural engineers, the annual conference of the state association could not have come at a better time.

Gathering last week in this seaside suburb of San Diego, the Structural Engineers Assn. of California reviewed a new code toughening construction standards and traded war stories and lessons from the Whittier quake. The most sobering message for these can-do professionals was that their designs and calculations do not always provide enough protection.

John M. Coil, the organization's outgoing president, grimly warned members that the Whittier earthquake, as bad as it was Oct. 1, is far from the worst that is expected.

"I don't think we're prepared. I don't think we're anywhere near prepared," he said.

Chris Poland of San Francisco began a slide show of damage from the Whittier quake with a sermon for his fellow engineers to get out from behind their personal computers and go see for themselves what a quake can do.

"I hope you all went down to Whittier, or you'll go," he said. "It's real important for you and all your staff members to see actual earthquake damage, especially that closes people down.

"Interact with the people a little bit--the shopkeepers, the people who are trying to live in their homes. Come to grips with what we are really doing here in structural engineering."

With that exhortation in mind, an audience of several hundred listened carefully to a highly technical presentation of the model building code with more stringent earthquake hazard reduction measures.

The model code, which was adopted last month by the International Conference of Building Officials, was drafted over the last eight years by the California structural engineering association in a voluntary effort that took an estimated 10,000 hours and cost more than $1 million.

Warren O'Brien, assistant general manager of the Los Angeles Department of Building and Safety, said Los Angeles, whose code already includes some of the innovations of the model code, will probably adopt it sometime in 1988, when it is published. Allan M. Porush, outgoing chairman of the code drafting group, said most local jurisdictions west of the Mississippi are expected to adopt it.

Porush, who works for the Dames & Moore engineering firm in Los Angeles, said a major earthquake would still harm buildings designed to the standards of the model code.

But he said if all the buildings hit by the Whittier quake had been designed according to the new code, the damage, now an estimated $177 million, would have been at most one-tenth of that.

For new construction, the additional cost of following the new code would be less than 1%, Porush said, adding that it could reduce quake damage by 5% to 25%. The cost of bringing an older building up to the standards of the code, which many jurisdictions require during major renovations, could vary from 5% to 50% of the building's replacement cost, he said.

Compared with the old model code and the building code now in effect in Los Angeles, the new regulations are far more specific in how the main structural elements of a building should be fastened to one another, spelling out the number of bolts, welds or stiffener plates.

In addition, the new code will require a computer-modeled analysis for most buildings with asymmetrical shapes to determine how they will hold up under an earthquake--a requirement Los Angeles imposed in 1976.

In place of a single sentence in the old code about industrial facilities such as refineries, the new code contains two pages of requirements followed by several pages of tables for engineers to use.

"This is a major change in procedure," said William E. Gates, another Dames & Moore associate.

State seismologist Carlos Ventura presented freshly gathered data to the group showing that specific buildings were hit with unexpectedly large forces during the Whittier quake.

The quake struck the top of the nine-story administration building at Cal State University, Los Angeles, which is about 6 miles from the quake epicenter, with almost half the force of gravity, he said. In Burbank, about 15 miles from the quake, the top of the 10-story Pacific Manor building was rocked with an even stronger force.

"I hope it settles in, in your mind, how large those accelerations were in those buildings," said Poland, whose slide show of quake damage followed Ventura's data presentation. "The thing we are going to have to wrestle with is how well those building are doing with those high accelerations."

Right after the quake struck, Warren O'Brien, assistant general manager of the Los Angeles Department of Building and Safety, told members he was feeling confident.

"I was content in feeling that, at that moment, I was in charge of the largest building department and the most sophisticated building department as far as I am concerned in the nation and probably in the world. We had a very detailed emergency operation program.

"With all that, things started going wrong."

He tried to call his district offices. The phones did not work. Earl Schwartz, director of emergency operations, was stuck in a freight elevator. "I was in charge because our general manager was stuck 20 miles out of Los Angeles on a train," he said.

"To top all this off, the Fire Department started going through the building telling everyone to get out. That's what happens to the best of plans."

Eventually, O'Brien said, hand-held radios provided communications and operations were directed smoothly from a basement emergency communications center.

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