Construction Standards for Tsunami-Prone Schools

Tsunami

• An earthquake results from shifting movements of the Earth or from volcanic activity. Those places that lie above the meeting of shifting tectonic plates are prone to volcanic activity. A force that resembles a wave travels through these areas and its impact depends on the geological characteristics of the areas. When the source of the earthquake lies underwater, this force creates a tidal wave, or tsunami.

Structural Element Connections

• The connections between school building walls, floors and roofs are significant stress points, and their design should make them stronger than the connecting elements, according to the INEE. Each element of the box shape depends on the other elements, and they should be safely fastened together. The structural system should be firmly stuck to the foundation. If not, there is a possibility it may shift or slide when a tsunami strikes.

Site Selection

• In selecting a site for school construction in a tsunami-prone area, the INEE recommends a site as far away as possible from earthquake fault lines. The site should minimize any potential earthquake damage and should be made of the firmest subsoil possible. Select a site that is sufficiently high enough to avoid the impact from the highest tsunami waves. Consider sites that are close to structures that could provide refuge to the school's occupants in an emergency.

Design and Construction

• In choosing a building design, the INEE advises that it is best to avoid asymmetrical "U" and "L" shapes that tend to be vulnerable to earthquake and tsunami damage. In cases where the school building has more than one story, the building design should be such that each story has an equal capacity to resist lateral forces. Typically, if a lower floor has a lower resistance, it tends to collapse and damage the entire building.