Project Impact School Non-structural Mitigation

Letter from a Seattle School after the February 28th Earthquake:

Theresa (Seattle School District),

Just wanted to let you know the good news on how well Mercer (the building) did during the earthquake --- and a big thanks for the retrofitting. We did not even have a single light cover come down, a computer fall over, a book come off a shelf.

Now, ...... how do we get more straps to do the new things we have installed since retrofitting was done here. Think you made believers out of us.

Thanks,
Shirley Swindler, Nurse
Asa Mercer Middle School

Overview

Substantial damage to Seattle schools in the 1949 Olympia and 1965 Seattle-Tacoma earthquakes generated a heightened awareness of the vulnerability of school buildings to earthquake ground shaking. The magnitude 7.1 1949 earthquake damaged 21 schools in the Seattle School District, resulting in the temporary closure of five schools and the condemnation of three. The magnitude 6.5 1965 earthquake resulted in the closure of eight schools, including two in West Seattle that were extensively damaged. Most damage occurred to older unreinforced masonry (brick) buildings with inferior mortar.

Over the past 30 years the Seattle School District has identified and removed the most pressing school earthquake hazards. The district has concentrated on large structural projects to either replace or seismically strengthen facilities. However, special attention must also be paid to seismically securing nonstructural items, such as chemicals in high school science labs, mechanical and plumbing systems, and natural gas equipment.

How Are Project Impact Funds Being Used?

Money from the City of Seattle's Project Impact grant enables the district to further improve the safety of schools by focusing on three specific areas:

• Removing Overhead Hazards.
  Several schools use heavy overhead flush tanks and radiators as part of their plumbing and heating systems. During an earthquake, these elements present a significant hazard if they become dislodged and drop on someone. The district has replaced, replumbed, or removed the overhead hazards at 46 sites. During the February 28th quake, one of the drained 300-gallon flush tanks had broken loose of its cables. If the tank had been full (weighing over 1 ton) and unretrofitted, the potential for extensive damage and injuries to the full classroom below would have been high.



• Establishing & Training Self-Help Mitigation Teams.
  The district is using part of the grant money to update the Superintendent of Public Instruction's 1988 manual on Mitigation of School Earthquake Hazards to reflect current nonstructural mitigation practices. This new Nonstructural Protection Guide has been used to implement training for a self-sustaining program that trains maintenance staff to identify nonstructural classroom hazards that can be fixed by school volunteers. Maintenance staff, in turn, will train these volunteers to use "nonstructural retrofitting kits" to correct the identified hazards during a 1/2 day Saturday Work-Party. All School District Zone Crew Supervisors, Maintenance and Custodial staffs have attended training. Nonstructural retrofit (which ties down computers, equipment, bolts shelves, straps TVs, braces machinery, etc.) has already been completed in 10 schools and one is in progress. At the time of the February 28th earthquake, 7 schools had been retrofitted by volunteers during Saturday Work-Parties. In those 7 schools, there were no injuries or damage.
  
  Tied to this retrofit component is an educational opportunity which includes a "Hazard Hunt" for students to participate in reducing their risk at school and home, a poster/essay contest describing their ideas, and general education of our region's earthquake hazard. All of the educational outreach contains messages to be carried home.



• Investigating Advantages of Installing Automatic Natural Shut-Off Valves.
  During and after an earthquake, natural gas leaks may present a significant hazard in some situations. Puget Sound Energy is working with the School District to review the merits of automatic vs. manual shut-off valves in an effort to minimize the risk of these leaks. The District has installed 3 shut-off valves in 2 schools. Due to the ground shaking on February 28th, all 3 of the gas valves' mechanisms shut-off their gas supplies. There were no reports of gas leaks.