ABSTRACT
The damage caused by natural disasters can be considered in various ways. This chapter considers how a building performs under stress, the hazard that has received the most attention is that posed by earthquakes. It provides a sort of prototype for the study of other disasters. Construction failure is the principal threat to life and limb during an earthquake. Seismic damage to buildings often seems inexplicable: the visual impression may be one of total destruction with no apparent pattern. However, damage is not random, although it is likely to be complex and perhaps poorly understood. The nature of earthquake damage has been known in principle since 1860 with respect to masonry buildings, and since the early 1900s with respect to steel-frame and reinforced-concrete construction. Each earthquake yields unique combinations of intensity, duration and type of vibration. The ground waves comprising this mixture vary from those with periods of seconds to those so fast that they set up an audible hum.
