[LA FEATURE] Earthquakes


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Earthquake Safety: Focus Renews on Potentially Vulnerable Concrete Buildings

Data analyzed by the NBC4 I-Team finds that the maximum potential occupancy of those buildings is nearly half a million people.

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    A new study of Los Angeles concrete buildings reveal nearly 1,500 that are potentially vulnerable in a major earthquake. Schools, churches, hotels and hospitals are among the list. Patrick Healy reports for the NBC4 News at 11 p.m. Tuesday, Jan. 21, 2014. (Published Tuesday, Jan. 21, 2014)

    How safe is your home, your child’s school or your office in the event of a major earthquake?

    Engineers have identified nearly 1,500 older concrete buildings in Los Angeles that they believe deserve a closer look to determine if they are vulnerable to temblors.

    Survey Shows LA Buildings Most At Risk for Next Earthquake

    [LA] Survey Shows LA Buildings Most At Risk for Next Earthquake
    A new survey shows the Los Angeles buildings that would be most at risk if an earthquake were to hit Los Angeles. Older concrete buildings such as schools, churches, or office buildings, may not have adequate reinforcing to withstand a big quake. Patrick Healy reports from Hollywood for the NBC4 News at 6 p.m. on Jan. 21, 2014. (Published Tuesday, Jan. 21, 2014)

    Los Angeles city officials are now getting all the data, including the exact addresses, of thousands of structures that may not have adequate reinforcement to survive a significant quake. But the city is grappling with whether to give those addresses to the public.

    Special Section: Earthquake Info, Maps, Resources

    “I have a concern and the researchers on my team that people could become unduly alarmed and take a course of action that is really not warranted by this database,” said Jack Moehle, Ph.D, an engineering professor at UC Berkeley.

    Moehle and his team found 1,454 concrete buildings in Los Angeles that may be inadequately reinforced. On the list are dozens of churches, offices, apartment buildings and theaters, and schools.

    More specific numbers of buildings include:

    • Commercial: 235
    • Schools: 214
    • Churches: 48
    • Hotels: 47
    • Hospitals: 45
    • Theaters: 21
    • Shopping Malls: 15

    Data analyzed by the NBC4 I-Team finds that the maximum potential occupancy of those buildings is nearly half a million people.

    But Moehle said there’s a significant caveat when it comes to his data.

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    “Some of these buildings are perfectly safe in their current condition, some of them may already have been retrofitted but there will be some within this inventory of buildings that are likely to be judged as vulnerable,” he said.

    Renewed attention is being put on concrete buildings without more steel reinforcement than was thought necessary when they were built.

    Quake shaking can cause vertical supports to fall, and when that happens, the building collapses into rubble and casualties are almost a certainty, Moehle said.

    More than 120 people were killed when two such buildings collapsed during the 2011 New Zealand quake.

    Determining the risk level in LA will require individual engineering inspections yet to be done. But for now, those who live, work and play in older concrete buildings will not be told if they’re on the list.

    The portion of the report being made public reveals only rough geo-coordinates, not exact addresses. A map of the available information is embedded below.

    Last fall, some prominent buildings, including Capital Tower and Pantages Theater, were identified in a survey by the Los Angeles Times as vulnerable to quakes. Last week, the LA City Council supported pursuing the resources to perform inspections of potentially at-risk buildings, but as of now, there’s no plan or funding in place.

    “I would hope that some action would be forthcoming,” Moehle said. “It is a real opportunity to make a difference for seismic safety.”

    After the deadly 1994 Northridge quake that devastated the Southland, Los Angles passed a retrofitting ordinance for the so-called non-ductile concrete buildings. But it was not retroactive and existing concrete buildings must be reinforced only if they get a major quake makeover or repurposing.

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