Tectonic hazards/Earthquake loss estimation

Earthquake loss estimation, required for the seismic fitness considerations, is usually performed in terms of a Damage Ratio (DR) which is a ratio of the earthquake damage dollar amount to total value of a building. For a long time, it was associated with a collection of mass inventory data and was based, mostly, on experts' opinions. It looked, therefore, more like an art than a science.

A considerable step forward was made with the completion of project called HAZUS offering a fully computerized procedure for loss estimation. However, motion-damage relationships of HAZUS are not written in the building code language. Besides, they are based, at least partially, on experts' judgments valid just for an average construction and, therefore, most applicable for a statistically large number of facilities.

There is, also, the Damage Ratio Charts Method which is based on a consistent quantitative analysis targeting a prediction of damage ratios and employs a limited number of well-understood structural and earthquake related parameters. It establishes a direct theoretical relationship between the standard structural design procedure and the expected damage characteristics required by insurers.

The method is user-friendly: its application, supported by a site-specific evaluation, does not take more than a few days.