Unreinforced Buildings Stir S.F. Quake Concern

In a city that many might think would be the capital of earthquake preparedness, there are more than 2,100 unreinforced brick buildings in use here that experts say are sure to collapse when the next big one hits.

City officials know of the danger. In fact, it was city engineers who identified the unsafe structures four years ago. Furthermore, San Francisco law contains strict, continually updated seismic building codes.

However, the codes have a loophole. They pertain only to buildings erected after 1948. Th ere is no legislation requiring owners to reinforce unsafe buildings that went up before that.

Engineers have known since the 1930s that these older brick homes, apartment houses and offices--called unreinforced masonry buildings or UMBs--cannot withstand a severe side-to-side shaking. But they continue to be occupied, mostly in the Chinatown and low-income Tenderloin districts of the inner city.

Those concerned with official inaction say the reasons have nothing to do with safety and everything to do with politics. Elected officials fear the fallout from landlords and tenants who foresee rent increases that could drive low-income residents out into the streets. City officials also say other problems--such as homelessness or the AIDS crisis--take precedence in the order of chronic woes they address.

“If disaster strikes, we’ll say it’s terrible, why didn’t we do something?” said city Supervisor Tom Hsieh. “Until you see the blood, I guess nothing’s going to happen.”

Those supporting a tougher approach say San Francisco should copy Los Angeles, which enacted legislation in 1981 requiring landlords to make their buildings structurally sound.

San Francisco city planner Paul Deutsch agrees and notes that there are official moves in that direction. But Deutsch says that his city--by conducting an environmental impact study before it takes action--is trying to avoid some of the pitfalls Los Angeles has encountered.

The Los Angeles ordinance requires all property owners with UMBs to reinforce their buildings and complete the work by 1992. Reinforcing methods include anchoring wood frames together with steel bolts, spraying reinforced concrete on the walls and strengthening roofs and supportive interior walls by adding plywood, according to Karl Deppe, chief of earthquake preparedness in the city’s Building and Safety Department. About 5,000 of Los Angeles’ approximately 8,000 old brick buildings have been strengthened or work is under way and 1,000 have been torn down, he said.

But among the upgraded buildings, rents have increased an average of $70 a month per tenant, according to James Fleck, a Los Angeles city housing planner and economic analyst. In addition, because of the decision to tear down many old structures rather than bring them up to code, thousands of people have been displaced each year since the program began, he said. Where these tenants went is not known. “They move somewhere else or they move in the street,” Fleck said.

Deutsch fears a similar scenario could take place in San Francisco, where the 2,100 buildings identified in the 1985 survey include 25,000 residential units. He said there has been no specific count of the people living in shaky buildings, but he said estimates exceed 40,000.

In the meantime, a $60-million bond issue on the November ballot will request funds to be partially used for seismic improvements to public buildings, which make up 30 to 40 of the 2,100 deemed to be dangerous.

One of the problems facing seismic safety programs, adherents say, is that people tend to ignore life-threatening situations until disaster hits. So while many people associate San Francisco with the great 1906 earthquake that virtually leveled the city and killed 700 people, that 8.3 temblor occurred too long ago to frighten current city residents.

It was the 1933 Long Beach earthquake that prompted the first state legislation requiring earthquake safety standards on new buildings. That quake, at magnitude 6.2, damaged more than 86% of the city’s unreinforced brick buildings, according to Deppe, and erased any doubts about the danger of brick buildings in earthquake country. Unlike wood frame or steel structures, buildings made of brick have no elasticity and, if they are old, are frequently held together with deteriorating mortar that disintegrates under pressure, according to Frank Lew, San Francisco seismic safety program manager. In the jarring of a quake, the bricks separate, he said.

“Once that happens, you’ve lost the bearing and support and the walls come tumbling down on your head,” Lew said.

Aware of the danger, the city in 1948 prohibited construction of buildings that could not sustain minimal damage during a minor earthquake. The new codes required builders to use wood frames, attach frames with steel bolts or construct inside walls designed to provide interior support to a building, Lew said.

Yet no such standards were applied to San Francisco’s many brick buildings built earlier. Nor, for that matter, were earthquake safeguards ever required on the estimated 35,000 other such buildings in the seismic region stretching from the San Francisco Bay Area to Los Angeles, according to Fred Turner, staff structural engineer for the governor’s seismic safety commission.

To force the issue and require retrofitting of old buildings is “an expensive proposition,” said Deutsch. “It takes new and bigger earthquakes to provide the political will to do something about it.”

Jim Usui, senior structural engineer for Los Angeles’ earthquake safety agency, agreed that making old buildings earthquake-safe is not just a matter of construction. If costs are too high, owners tend to try to raise rents, sell out or convert the property, he said.

Meanwhile, those with no direct stake in the buildings tend not to be concerned until disaster strikes. “All of this adds up to a political problem,” Usui said. “It takes a major occurrence like the (1971) Sylmar earthquake to drive the politicians and everybody along to get these buildings improved to a level of safety.”

Lacking a destructive quake in recent memory, San Francisco’s efforts at upgrading risky buildings remain stalemated. The only progress the city has made in the four years since its survey of UMBs has been to allocate $500,000 for the environmental impact report.

“It’s such a horrible either/or thing,” said Brad Paul, deputy mayor for housing and neighborhoods. “Faced with the choice of having people die in the future or spend the rest of their lives living in the streets, my guess is that politicians haven’t wanted to deal with it.”

Supervisor Hsieh, a former architect who witnessed 1987’s Whittier earthquake, fears that Chinatown and the Tenderloin could be reduced to rubble before the city takes action.

“I’m angry with the passive style of politicians on this issue,” he said. He said he saw how quickly an earthquake can take apart a brick building. For those inside, he said, “you don’t even have a chance.”