Buildings, houses, bridges, roads, underground water lines are all vulnerable to earthquakes. In many cases the disaster is the result of poor building practices. Buildings with foundations resting on unconsolidated landfill and other unstable soil, and trailers and homes not tied to their foundations are at risk because they can be shaken off their mountings during an earthquake. When an earthquake occurs in a populated area, it may cause deaths and injuries and extensive property damage. Buildings designed and constructed using out-dated methodology should be upgraded. Performance-based engineering should be emphasized, especially for the protection of building functions following frequent earthquakes.

Building control standards may have been non-existent, in practice and perhaps in statute? Unless the people find an organized economic alternative (aid?), they may continue doing what they always have done. Buildings have been designed according to an elastic design concept which requires that the stress of structural members of buildings should be lower than a predetermined value which is within the elastic range against design loads such as earthquakes. It is required, according to an elastic design concept, that the maximum stress should be within the elastic range and less than a predetermined magnitude against earthquakes of medium size which the building may experience relatively frequently; and less than the yield stress against ultimate earthquakes which the building may experience.

Actually it is one of the most important factor for a good building and if possible, the money saved from cost effective designs and technologies should be used for creating a maintenance fund by involving village community. Participatory process, thus, assumes great significance to generate the feeling of ownership amongst people. Actual ground motion accelerograms are selected and scaled to levels representing moderate and severe ground motions. Constraints quantifying structural damage and limited nonstructural damage are constructed for the case of moderate ground motion.

Shear walls, in particular, must be strong in themselves and also strongly connected to each other and to the horizontal diaphragms. In a simple building with shear walls at each end, ground motion enters the building and creates inertial forces that move the floor diaphragms. Shear walls, made of reinforced concrete (concrete with steel rods or bars embedded in it), help strengthen the structure and help resist rocking forces. Shear keys at either end of the span provide transverse restraint with one end fixed longitudinally. Bored piled foundations of 2m diameter and up to 60m long support the viaduct.

1. Earthquake Resistance References