UC researchers have recently released a spreadsheet of nearly 1,600 concrete buildings in Los Angeles that don’t meet current codes for earthquake safety to LA city officials — a list that researchers were initially hesitant to release last October.
The list identifies concrete buildings in highly seismic zones of LA constructed prior to the mid 1970s, when codes for concrete were enforced. Because the list was then only preliminary data — and could easily be misconstrued as a list of hazardous structures — researchers have waited until late last month to release the detailed data to the city.
In October, the authors — led by UC Berkeley engineering professor Jack Moehle — released to LA city officials a database of the approximately 1,600 buildings, which detailed building size, age, type, usage and ownership type, but excluded the identities of the buildings.
“We didn’t feel that it was appropriate to release the data on the individual buildings last fall because we had not yet finished our study,” said UCLA civil engineering professor Jonathan Stewart, a co-author of the report. “We did not want to cause public panic by releasing data that was not directly important to our study.”
Jennifer Strauss, external relations officer of the Berkeley Seismological Laboratory, explained that the south San Andreas fault, located in Los Angeles, is at great risk of experiencing an earthquake of magnitude 6.7 or higher, much more so than the north San Andreas fault that runs through San Francisco.
In 1971, an earthquake in San Fernando Valley, right outside of Los Angeles, caused several concrete buildings to collapse, killing about 50 people.
In light of Los Angeles’ precarious situation, Stewart suggested that city officials, now equipped with the official list, create their own inventory of these “nonductile concrete” buildings, gather experienced engineers to more expertly confirm which buildings are in fact still safe and retrofit those at most risk of collapse.
But Robert Steinbach, chief of the inspection bureau at the Los Angeles Department of Building and Safety, explained that economic considerations need to be made before the city of Los Angeles can even begin considering retrofitting its potentially unsafe buildings.
Steinbach added that he is wary about retrofitting these buildings solely because they do not meet current codes, as such regulations are always subject to change in the future as technology advances.
“The sheer economic issues that could be raised on this is really something to consider,” Steinbach said. “You’re talking about people being kicked out of their homes possibly … It can be really devastating if it is not handled properly. And ultimately, when you’re all done, I don’t know that you can ever really retrofit a building to make it meet current code standards.”