The Importance of Resilient Communities During Earthquakes

Imagine that it’s 4:30 a.m. and suddenly you’re awakened by strong shaking in your home. Half asleep, you hang on to your bed hoping that the shaking will stop soon. All of a sudden, the floor gives away and you fall. You think, “What just happened? How could this have possibly occurred? Am I alive?”

These could have been the thoughts of Southern California residents living in one of the many apartment buildings, which collapsed on January 17, 1994, during a 6.7 magnitude earthquake. The Northridge Earthquake brought awareness to buildings in our communities with a structural weakness known as a soft story, a condition that exists where a lower level of a multi-story structure has 20% or less strength than the floor above it. This condition is prevalent in buildings with tuck-under parking and is found in multistory structures throughout San Francisco, Los Angeles and other cities (see Figure 1). These structures are highly susceptible to major damage or collapse during a large seismic event (see Figure 2).

Soft Story building
Figure 1: Multi-unit wood-frame building with first weak story.
Aftermath of an earthquake
Figure 2: Collapsed soft story tuck under parking building. Image courtesy of LA Times

Soft story retrofits help to strengthen our communities and make them more resilient to major disasters. There are several resources available to structural engineers that need to retrofit weak-story buildings. Some of these resources are mentioned in our September 18 blog post.

During the 2014 SEAOC Convention held in Indian Wells on September 10-13, speakers discussed different methods, analysis and research that address the behavior of various materials and construction types during seismic events along with approaches to retrofit historically poor performing structures. This information can be viewed from the convention’s proceedings available at www.seaoc.org.

On October 20, 2014, the Structural Engineers Association of Southern California (SEAOSC) will be hosting their 4th annual Strengthening Our Cities BAR Summit in downtown Los Angeles. This event brings together many different stakeholders in our built environment, including public officials, building owners and managers, business owners, insurance industry representatives, emergency managers and first responders, and design professionals.

Many prestigious thought leaders, including USGS Seismologist Dr. Lucy Jones will be speaking at the summit, discussing such topics as tools and analysis methods for retrofitting vulnerable buildings and the Building Occupancy Resumption Program (BORP).

Expect a great day full of useful information about ways to strengthen our communities and prepare for major earthquakes as well as opportunities to network with like-minded peers. For additional information and to register, visit www.barsummit.org. We also hope you’ll visit our booth. We look forward to speaking with you there.

2013 Buildings At Risk Summit Focused on Individual and Community Safety, Resiliency

Guest blogger Jeff Ellis, engineering manager
Guest blogger Jeff Ellis, engineering manager

The Structural Engineers Association of Northern and Southern California hosted the third annual Buildings At Risk ǀ Earthquake Loss Reduction Summit in Los Angeles on October 8 and in San Francisco on October 15. Robust panel presentations and discussions presented by professionals from diverse yet complimentary fields targeted a mixed audience of building owners, architects, engineers, government officials, insurance representatives, and financial industry representatives.

2013 BAR Summit Los Angeles. Image credit: SEAOSC.
2013 BAR Summit Los Angeles. Image credit: SEAOSC.

The first panel, The Single Building and the City: Why Every Building Counts, discussed community vulnerability due to our increasing interconnectivity and how the demise of certain individual buildings from a seismic event could have large detrimental affects on the initial response and recovery of the city or the region they’re located within. Buildings which house important or widely used computer networks and servers or the major employer of a community are just a few examples.

BAR Summit Panel 2: The Current Situation. Image credit: SEAOSC.
BAR Summit Panel 2: The Current Situation. Image credit: SEAOSC.

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