Natural Disasters - Earthquakes, Tsunamis & Flooding
Intro
To be sustainable, a facility’s design and construction must be appropriate for its local climate and geology, including a capability to withstand the typical natural disasters to which its location is subject. In Oregon that means all schools must be prepared for earthquakes, and those in flood plains or tsunami zones must also be built with the appropriate considerations. Many of Oregon’s school buildings are over 50 years old, and were built before the potential damage from such natural disasters was so well understood.
Summary of Seismic & Tsunami Inundation Study of Oregon’s Schools
In 2005 Oregon’s legislature passed SB 2, which directed the Oregon Department of Geology and Mineral Industries (DOGAMI) to develop a statewide seismic needs assessment, including seismic safety surveys, of K-12 public school buildings that have a capacity of 250 or more persons, and other selected public facilities.
Related legislation passed concurrently outlined a seismic rehabilitation grant program (SB 3) and a supporting bond program (SB 4).
The assessment looked at these key factors:
- Seismic hazard zone (high vs. low history/probability of earthquake)
- Building structural type (wood, concrete, masonry, reinforced, etc.)
- Original construction date
- Soil type (dense to soft)
The assessment also incorporated a “Rapid Visual Screening” process for each building.
This data was then used to assign scores to each school building based on how the building might behave in a maximum strength potential earthquake. Using generalities based on the above factors the assessment helps to understand the scope of this seismic concern, but it was not a comprehensive structural assessment and did not consider building-specific factors or completed mitigation projects. Many districts have completed either a local evaluation or local building upgrades. The majority of the schools being assessed were built in the 1945–1975 period, before either seismic zones or building codes were updated based on a heightened awareness of earthquake and tsunami potential in Oregon. The assessment also considered the risk posed to buildings by their proximity to the tsunami inundation zone.
The seismic needs assessment final report was released in July 2007. It found that of 2369 public school buildings in Oregon, nearly one half have high or very high risk of sustaining life-threatening damage in a maximum-case earthquake. The report is only the first step in a multi-part process that will eventually create a pool of state money for seismically retrofitting eligible buildings (Senate Bills 3 and 4).
The report also states that of the 150 sites along the Oregon coast studied for potential risk of tsunami inundation, 48 sites have moderate to high risk, and another 81 sites have lower tsunami inundation risk.
Resources
Oregon Department of Geology and Mineral Industries (DOGAMI) website projects page:
http://www.oregongeology.com/sub/projects/rvs/default.htm. (Links on the right lead to the report, individual school assessments and a helpful FAQ).
Oregon Department of Education Quake Safe Schools page:
http://www.ode.state.or.us/search/page/?id=2061,
Oregon Department of Education Emergency and Information Planning page: http://www.ode.state.or.us/search/results/?id=372
PBS's The NewsHour reports on efforts to learn from China's devastating earthquake and to boost efforts to secure America's schools.
View the video via this link.