Strategies for Mid-America Residential Retrofit
One of the many uncertainties expressed by academia, personal line insurers, and homeowners is the ability of residential structures to survive damage from moderate to large earthquakes. US seismic zones with relatively short recurrence intervals between damaging events have mandated strict building and retrofit codes because the population and infrastructure undergoes damaging ground motions every few decades. Because no significantly damaging earthquakes have occurred in Mid-America since 1895 (magnitude 6.2, Charleston, MO) and the recurrence interval between damaging events is long (70 to 90 years, magnitude 6.0), most of the residential inventory has not been built to any seismic code and is vulnerable to moderate ground shaking. Thus, the earthquake damage potential of Mid-America is commonly characterized as “low recurrence, high consequence”.
Well-established retrofit standards have evolved over the past decade by integration of knowledge gained from the performance of residential structures in the Loma Prieta and Northridge, CA earthquakes. This information was collected by the Seattle Project Impact Home Retrofit Project Team and was organized into a 3 manual plan set. The SMARRT manual will incorporate this current West Coast retrofit information. The digital information will be edited where necessary to better conform to the common framing and foundation construction practices of the Central U.S. Local building officials and engineers will be consulted for further revisions of SMARRT products.
Information on the general earthquake hazard faced by Mid-Americans can be found in US Geological Survey Fact Sheet-2006-3125, “Earthquake Hazard in the Heart of the Homeland”.
know about earthquakes in Mid-America?
Click an image below.
Want to know how you can prepare your home?
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Video of the Two-Story House Shake-Table Testing at the University of California at San Diego
Permission to re-use this footage is granted by and credited to:
- Consortium of Universities for Research in Earthquake Engineering (or CUREE)
- University of California at San Diego
- Federal Emergency Management Agency
The earthquake shaking provided by the shake platform replayed the actual motion of the ground that occurred in an area where the shaking was intense in the January 17, 1994 Northridge (Los Angeles) Earthquake, except that this shake table moved back and forth in one direction whereas actual earthquake motions are a combination of horizontal motions in various directions, along with some vertical motions.
|Click the movie below to see ideas for retrofits|
|The Virtual Building Retrofit Demostration was created by Brad Cross and Scott Smith at Southern Illinois University Edwardsville. The building used and digitized was the Public Education Resource Center at the Center for Earthquake Research and Information at the
University of Memphis. Visit http://www.ce.siue.edu/earthquake/ for more information.
poster provides visuals and descriptions so that homeowners
can identify and fix at-risk areas of their homes to reduce
future earthquake damage and disruption.
Comprehensive sites regarding retrofitting:
|Take a second and tell us what you think!|
|Funding for SMARRT in part by the National Earthquake Hazard Reduction Program and State Farm Insurance.|