Steel-Frame Construction Methods Backed

Despite widespread evidence that construction techniques for steel-frame buildings failed during the Northridge earthquake, building owners will be allowed to use the same methods to repair the damage, Los Angeles city officials said Tuesday.

Citing concerns about the high cost to inspect and repair such buildings, a city panel recommended that building owners be allowed to devise their own inspection and repair plans using current repair methods.

Building officials defended the decision, saying that current technology kept steel-frame buildings from collapsing. They added that government-funded studies of quake damage have yet to provide new repair methods.

After the Northridge quake, engineers were surprised to hear widespread reports of cracks in the joints of steel-frame buildings because such frames are designed to bend with the enormous force of an earthquake without breaking.

Engineers emphasized that no steel-frame buildings came close to collapsing in the quake. However, an 11-story Westside structure was evacuated two weeks ago after engineers discovered the steel-framed building had been dangerously weakened.

The owners of about 300 steel-frame buildings in the high-damage areas of the San Fernando Valley and the Westside will be required to self-inspect steel joints within three months of notification by the city, under a recommendation approved by the City Council’s Ad Hoc Committee on Earthquake Recovery.

Building owners will be allowed to use current repair methods, pending a case-by-case approval by city inspectors. It will be up to the building owner to use higher repair standards to increase the strength of steel joints so they can withstand subsequent quakes.

The repairs must be completed within two years of the inspection.

Inspection charges alone can range from $10,000 to $60,000 per building. But the cost can be cut if building owners devise their own inspection and repair plans tailored to their particular facility and the amount of damage suffered, said Richard Holguin, assistant chief of the city’s building bureau.

Building officials had previously suggested a strict set of rules for inspecting steel joints and recommended a shorter, one-year time limit for owners to make repairs.

Holguin rejected suggestions that building owners and their engineers might take advantage of the liberal guidelines and make only minimal repairs.

“A structural engineer who does that would be putting his license on the line,” he said. “I don’t think from a practical standpoint that will happen.”

Geoff Ely, executive director of the Building Owners and Managers Assn., representing 1,500 members throughout Los Angeles County, said the proposal “made a lot of sense” and echoed Holguin’s sentiments that current repair methods are adequate.

“To repair the buildings to pre-Jan. 17 conditions certainly puts tenants in no greater danger,” he said.

Councilman Hal Bernson, who chairs the earthquake recovery committee and serves on the state Seismic Safety Commission, supported the building bureau’s recommendation but said he may propose a uniform repair ordinance once engineers devise new techniques and propose new repair guidelines in the future.

Depending on the results, Holguin said the city may require inspections of the remaining 600 steel-frame buildings, including those in Hollywood, Century City and Downtown Los Angeles.

Since the quake, state and federal officials have funded studies at USC and UC San Diego on the damage to steel-frame buildings in hopes of providing new repair guidelines to withstand larger quakes.

Rawn Nelson, president of the Structural Engineers Assn. of California, said the studies should result in some interim repair guidelines to be published next month. But he said final recommendations will not be published until February, at the earliest.

“The industry is . . . trying to gather more test results from what happened in the Northridge quake so we can make recommendations based on fact, not theory,” he said.

Nelson and other industry engineers said the city’s decision to require inspections and repairs before final repair guidelines are proposed is reasonable, considering the alternative is to do nothing or impose guidelines that are not yet proven.

“There are still a lot of open issues, so people just have to use their best judgment and proceed,” said Nestor Iwankiw, director of research for the American Institute of Steel Construction Inc.