Editorial: What happens to Los Angeles when we survive the Big One but our buildings don't?Los Angeles Times — Los Angeles Times
March 12-- When the Big One-or even just the next Northridge-sized quake-hits Los Angeles, you will probably survive it. Between existing seismic codes for new construction and the ongoing mandatory retrofitting of concrete and soft-story wood buildings in the city of Los Angeles and beyond, most buildings should withstand a catastrophic earthquake well enough for you to make your way out of the wreckage when the shaking stops.
But those standards are designed just to keep buildings from collapsing. In a major earthquake, buildings could be so badly damaged that they are uninhabitable for months-or altogether beyond repair. With hundreds of apartment buildings, offices and supermarkets out of commission, Los Angeles would be a crippled metropolis. You think we have a desperate housing shortage now? Wait until an 8.2 hits on the San Andreas fault.
In an effort to prevent catastrophic property damage, California Assemblyman Adrin Nazarian (D-North Hollywood) has introduced a bill directing the California Building Standards Commission to strengthen the building codes governing the construction of larger apartment and office buildings and some commercial buildings. Instead of being designed just to preserve the lives of their occupants, AB 1857 would require all new "engineered" buildings to be sturdy enough to function-perhaps with some minor repair-and be reoccupied quickly after a major earthquake. That means making them about 50 percent stronger than current standards. The new standard would apply to schools, hospitals and other public buildings only if it is more stringent than their current codes.
The proposal is one of two Nazarian bills aimed at earthquake resiliency. The other, AB 2681, would require all cities to compile a list of seismically vulnerable buildings, although it would not mandate any retrofitting.
AB 1857 is a smart step toward recognizing the vital need for functional infrastructure in an earthquake-ravaged city. Seismologist Lucy Jones, who helped Los Angeles city officials craft their landmark retrofitting ordinance, has long advocated for building codes stringent enough not just to save lives, but to save buildings. According to Nazarian's office, earthquake models predict that half of the buildings built to the current codes would be so damaged by a major temblor that they couldn't be used.
University of Colorado at Boulder professor and engineer Keith Porter estimates in a study that even if every building was completely up to current California codes, a "Big One" (such as a 7.0 on the Hayward fault through a densely populated part of the Bay Area) could displace enough people to replicate the kind of exodus that happened in New Orleans after Hurricane Katrina in 2005.
Jones says that requiring buildings to be built strong enough to be functional adds only 1 percent to 2 percent to the cost of new construction. She bases that assumption on estimates from a number of studies by engineers, including Porter, who calculates that a tiny fraction of the costs involved in erecting a new office building stem from using earthquake-resistant materials. Increasing the resilience of those materials would not substantially increase the cost of a building, he contends.
Some representatives of trade organizations for building owners are skeptical about the low cost estimate. Nazarian should hear out their concerns and, if they're right, come up with a more realistic projection. But while it's important to have a clear idea of how much the bill might add to the cost of desperately needed housing and other projects, lawmakers should bear in mind the potential long-term savings in insurance premiums and disaster relief. A 2017 study by the National Institute of Building Sciences showed that every $1 spent mitigating earthquake hazards saved $3 in future disaster recovery expenses.
The bill wouldn't mandate that new buildings be occupiable immediately after a major quake; instead, it would leave it to the Building Standards Commission to determine how soon new structures must regain functionality. It also notes that other factors may prevent buildings that comply with the new codes from being reoccupied-for example, disrupted utilities or damaged furniture.
Such caveats are probably unavoidable, and they don't diminish the importance of the new standard the bill would set. When we finally are hit with the huge earthquake that scientists believe is inevitable, having functional apartments, grocery stores and office buildings will mean for many people the difference between staying in Los Angeles and fleeing.
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