Many of Washington’s K-12 students attend schools that may not withstand earthquake shaking.
The Washington Geological Survey (WGS) recently received Capital Budget funding to work with the Office of Superintendent of Public Instruction (OSPI) and a team of structural engineers to assess the seismic safety of K-12 schools.
We plan to do engineering inspections of approximately 220 K-12 school buildings and five fire stations. We will also perform geophysical surveys to establish the ground conditions and geology of each campus.
Conceptual retrofit plans will be produced for 20 of the selected schools.
Why This Project is Important
- 200 schools are within one mile of a known active fault trace
- 214 schools are in zones at high risk of liquefaction during an earthquake
- 72% of schools are within a high to very high seismic hazard zone
- Many of these schools do not have the needed seismic retrofits to withstand these effects
How Schools Benefit
This project will:
- help to inventory schools needing retrofits
- help to prioritize the retrofitting of seismically deficient schools
- help to locate sources of funding for the retrofits
OSPI is helping to select schools and contacting the school districts to determine feasibility at each campus. They are also attempting to determine the date of last major structural renovation for each building.
This summer, structural engineering firms will go to the schools to perform visual inspections.
The Washington Geological Survey will also conduct geophysical (seismic) surveys to determine ground conditions and geology at each campus. This information will inform the structural engineers about the expected shaking at each site during an earthquake.
More About Seismic Surveys
Seismic surveys rely on analysis of waves bouncing off subsurface layers. In active seismic surveys, the geophysicist creates a seismic wave by hitting the ground with a hammer. In passive seismic surveys, the geophysicist uses naturally occurring seismic waves or the “background noise” as the seismic source. Seismic surveys can be conducted on land or in the water—the effective depth of the survey may vary from tens of feet to several kilometers.
Seismic surveys involve sound waves generated from a sources that travel through the ground, are refracted, and are then received by detectors. The speed at which the waves travel tells us a lot about what layers are made of and how they are arranged.
Once all of the data is collected, it will be provided to OSPI for future use. Conceptual retrofit plans will be created for 20 of the 220 schools.