After driving away from the storms of May 20th and 31st ( we don't have a storm shelter) I have been ask by many friends and family - Can we build tornado safe schools in Oklahoma? The answer is yes. There are many ways to construct a school to withstand the forces of a large tornado. There are also many challenges including costs, how to retrofit existing schools, disruption of existing school operations, temporary facilities during construction, site restraints, political pressures and more.
Since the primary source of funding for public schools is tax dollars, school leaders are obligated and responsible for careful prioritization and use of those funds. The following information is presented to help school leaders, citizens and parents understand the variety of issues and options that may be available to them as they plan for storm safety in their district.
New School Options
A new school designed to be storm safe may cost $400.00 per S.F. for a poured in place or tilt-up concrete structure with impact resistant glass and all necessary lift and lateral load construction details to withstand up to 300 mph winds. The average size elementary school of 50,000 - 70,000 S.F. could cost between $20,000,000 and $28,000,000. Compare that to a elementary school with standard steel and masonry construction and able to withstand 90-120 mph winds and the cost for the same school of $175.00 per S.F. or $8,750,000 to $12,250,000. A increase of $11,250,000 to $15,750,000. Most would not consider that a viable option. In the same new elementary school, storm safe areas of 7 to 10 S.F. per student or 5000 S.F. may add from $500,000 to $800,000 to the initial costs of construction. The use of storm safe areas in new schools that also serve as computer rooms, music rooms, storage rooms and corridors are the most common approach for new school construction in Oklahoma.
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| Concrete Storm Shelter in Classroom of New Construction |
a.) Many older schools have structural systems of concrete block, steel and / or brick.
The challenge is to brace these for the wind loads and impact resistance that often come with large tornados.
It can be done to varying levels of performance with improved roof deck and edge lift resistance, additional diagonal steel bracing, foundation connection improvements, window glass replacement and many other items. The work may require extensive removal of interior and exterior walls, windows, floors and associated mechanical and electrical systems. These elements would typically be upgraded and/or replaced. It may also take several months which could affect school operations and seasonal need.
b.) New safe rooms adjacent to existing school facilities are another alternative. These can range from small reinforced concrete units to large multi-purpose buildings capable of housing all students and staff. Each school site may have area, access and adjacency limitations that could affect this option.
| Modular Concrete Units on School Site |
The key to improving storm safety starts with thorough evaluation of each school. Working closely with local school administrators; architects and structural engineers can review the storm safety plan, evaluate existing spaces, structural systems and other elements to determine the relative safety of the existing building. The team can then recommend various degrees of improvement strategies appropriate to the specific sites and help the district establish budget requirements and prioritize a improvement plan.
The value of a child's life is immeasurable and it's tragic that many children lost their lives on May 20, 2013. It our responsibility as community leaders to balance many competing influences and do the things that protect our children, families and loved ones in the future.
Photos Credits: Regency Steel Inc., thetennessean.com
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