Effects of steel-frame building damage reverberate through quake zone; solutions depend on testing - and a modicum of luck.

When city engineers "yellow-tagged" the four-story Sherman Oaks Atrium office building after the Jan. 17 earthquake, rendering it uninhabitable, the building's Boston-based owner vowed to get it repaired and reopened promptly.

Despite extensive damage to 41 beam-column connections in the steel-framed building, TA Associates Realty succeeded in getting its building repaired within five months. The bill: Less than $2 million.

The 94,000-square-foot building at 15315 Magnolia Blvd. was "green-tagged" as safe for occupancy on June 14. A few days later, tenants began moving back in.

About the same time Atrium owners were celebrating the reopening, however, structural engineers examining the nearby Sanwa Bank building were making a discovery. Similar ultrasonic tests revealed that 61,000-square-foot, steel-framed office complex at 15165 Ventura Blvd. also had beam-column connection failure.

The building, owned by downtown Los Angeles-based TCW Realty Advisors, had been green-tagged shortly after the earthquake. Now, some five months later, it was deemed unsafe.

Its tenants -- which include Sanwa Bank, Beverly Hills Securities, 1st Nationwide Bank, Transcapital Mortgage and Loma Linda Medical Center -- were forced to move out.

Structural engineers have also discovered similar damage to at least 90 steel-frame buildings, nearly all in the San Fernando Valley, according to Richard Holguin, assistant chief of the City of L.A. Building & Safety Department's building bureau. Another 900 steel-frame buildings in the L.A. area could be in jeopardy if another earthquake occurs.

In a problem unique to steel-frame buildings, the horizontal beams and vertical columns are welded together by a steel connection meant to withstand everyday gravity load, as well as resist an earthquake. In many buildings, that connection cracked either internally or externally.

To find the crack, engineers must go behind the drywall or tile, remove fireproofing material from the connection and then perform an ultrasonic test to see if there are internal cracks.

The University of Texas, which performed the ultrasonic testing last spring that revealed steel-frame buildings aren't as flexible in earthquakes as engineers previously thought, still doesn't know how to resolve the situation.

"The solutions depend on testing," said Bob Harder, manager of the Van Nuys office of the Los Angeles Department of Building & Safety.

The Los Angeles City Council's ad hoc committee on earthquake recovery, awaiting the results of follow-up testing by the University of Texas, has shelved consideration of a proposed ordinance that would require inspection of some 400 steel-frame buildings in the San Fernando Valley and on L.A.'s Westside that are susceptible to the beam-column connection damage.

Meanwhile, structural engineers and others in the local building community say they are cautious. "Retrofitting done today are possibly short-term retrofits," said Marc Caspe, a structural engineer with M.S. Caspe Co. in Los Angeles, who is working with TCW to get the Sanwa Bank building back on-line. "They may very well have to be retrofitted again."

The City of L.A.'s building and safety code states that a building must be returned only to the condition it was in prior to an earthquake.

Meanwhile, Atrium managers said they're confident the building is "safer than before the earthquake," and they are actively seeking tenants for available space.

About 35,000 square feet of space there is available for lease, said John Sabourin, a broker with commercial brokerage firm Lee & Associates in Sherman Oaks.

Sources close to the Atrium project said it was the bullish attitude of TA Associates Realty and the rapid pace at which the engineer, contractor and property manager pushed repairs along that brought the Atrium back so quickly.

It also had a lot to do with good timing, said Ric Kern, vice president with Newport Beach-based Davis Partners, which manages the Atrium. Right after the quake, structural engineers and contractors who had seen their workloads shrink in the recession were eager to jump on the quake-repair bandwagon.

Structural engineering firm Myers, Nelson, Houghton finished its analysis of the building by Feb. 9, and the building owner hired HBC Contractors, a Dallas-based general contractor, to repair the damage.

Meanwhile, the Sanwa Bank building sits vacant. Breaks were found in many of its beam-column connections, said Art Perez, a supervising engineer on the Building & Safety Department's disaster assessment team.

TCW would not comment on the Sanwa Bank building situation, although it has pulled a building permit for repairs.