Why do buildings collapse in earthquakes?
An Earthquake moves the ground. It can be one sudden movement, but more often it is a series of shock waves at short intervals, like our ripples from the pebble in the pond analogy above. It can move the land up and down, and it can move it from side to side. Therefore, it is not possible to design an earthquake proof building which is guaranteed to resist all possible earthquakes. However, it is possible during building design and construction process to build in a number of earthquake resistant features, which would increase enormously the chances of survival of both buildings and their occupants.
