The results can be puzzling. One house is knocked askew, walls crumbling, roof caving in; meanwhile, the one right next door appears to be virtually untouched. Why the difference? The greatest factor is the construction of the houses themselves. And the most important element of that construction is the foundation.
For homes built before the 1980s, there is often a simple explanation for the damage: the house was not properly attached to the foundation. If this is the case with your house, it is important that you contact a seismic retrofit specialist like Oregon Seismic to examine and, if necessary, perform the work necessary to bring your house up to code.
Fortunately, advances in structural engineering, lessons learned from past earthquakes and research performed by the scientific community have paved the way for the development of new retrofit techniques that better equip houses to withstand the destructive force of a massive earthquake. Reinforcing and upgrading a home includes bolting the house to its foundation, reinforcing the ‘cripple wall’ (the short wall between the first floor and the foundation), and shoring up the posts and beams that bear weight under a home.
It’s equally important to prevent fire or flooding that may occur as a result of a seismic event. A professional retrofit can include installation of an earthquake-activated gas shutoff valve, and the bracing and strapping of your water heater to prevent it from falling over. Aside from the danger of ruptured water and gas lines if this were to occur, this water may be the only accessible supply you’ll have. Even a little preparation can go a long way in the case of an emergency.
Your home is your biggest investment. Don’t leave it and your family unprotected. The time to do earthquake retrofitting is before an earthquake happens. The cost of the destruction that could occur will far outweigh the cost of the repairs — not to mention the peace of mind you and your family will get from knowing your house is safe.
The Oregon Resilience Plan https://multco.us/em/oregon-resilience-plan
The City of Portland Hazard Map: https://www.portlandoregon.gov/pbem/58572#maps
The Really Big One: An earthquake will destroy a sizeable portion of the coastal Northwest, The New Yorker http://www.newyorker.com/magazine/2015/07/20/the-really-big-one
Turbidite Event History—Methods and Implications for Holocene Paleoseismicity of the Cascadia Subduction Zone, U.S. Geological Survey http://pubs.usgs.gov/pp/pp1661f/
13-year Cascadia study complete – and earthquake risk looms large, OSU News & Research Communications http://oregonstate.edu/ua/ncs/archives/2012/jul/13-year-cascadia-studyco…
Analytical Baseline Study for the Cascadia Earthquake and Tsunami, Department of Homeland Security https://www.bluestonehockley.com/wp-content/uploads/2016/01/FEMA-earthqu…