August 23, 2011
Today’s earthquakes (EQ) in Virginia and Colorado occurred in areas not generally associated with earthquakes; a subtle reminder that ground shaking is not confined to California. While the Virginia EQ was not a particularly strong earthquake, it was felt over a very large area of the eastern US. As of 3:00 PM Pacific Time, there have been no reports of fatalities. In the epicentral area west of Richmond, VA, between Richmond, Charlottesville, and Fredericksburg, there will likely be some seriously damaged or collapsed buildings. Elsewhere, non-structural cracking and disruption of contents is expected. Serious damage in modern buildings is not expected, but is a possibility. The latest reports indicate minor to moderate damage to some buildings in the greater Washington DC area, with some partial roof collapses. Nuclear power plants in the area report safe shutdown and no damage. As a result of lower intensity ground shaking and sparse population, we do not expect to see much damage as a result of the Colorado EQ.
Exponent is exceptionally well qualified to assist clients with safety assessments (e.g., is my building safe for continued operations or re-occupancy?) and damage assessments (e.g., what damage did the earthquake cause and how might it be repaired?) for all types of structures including commercial, industrial, nuclear, infrastructure, and residential. Exponent engineers have extensive experience performing these activities following the Northridge Earthquake in 1994, the World Series Earthquake in 1989, as well as smaller events on the West Coast and Hawaii. Exponent also provides peer review of earthquake safety and damage assessment reports prepared by others.
Exponent staff are active in education and research in earthquake engineering. Exponent has sent reconnaissance teams to study structural and geotechnical damage resulting from major international earthquakes including China, Japan, Turkey, India, and Mexico City. Exponent staff serve as Structural Specialists on several FEMA Urban Search and Rescue teams and have been deployed to major US disasters. Exponent staff also serve as instructors training other engineers on topics of seismic risk assessment, safety and damage assessment, and rescue engineering and have published extensively on the topics of earthquake engineering, safety assessment, and damage assessment.
Below are links to two relevant capability pages from Exponent’s external website:
An excellent resource for information on both EQs is the USGS Earthquake website.
An excellent primer on earthquakes, their effects on buildings in general, and woodframe buildings in particular may be downloaded from: http://www.curee.org/projects/EDA/guidelns-award.html.
Click on [download basic version] below the yellow rectangle to download a color PDF of this 370 page book.
For further information, please contact:
John Osteraas, Ph.D., P.E.
Group Vice President & Principal Engineer