The solutions of many earthquake engineering problems involve dynamic analyses using time series. It is often desirable to base the selection of such motions on a probabilistic estimate of the seismic hazard. ÷robabilistic seismic hazard analyses (PSHA) is a technique for estimating the annual rate of exceedance of a specified ground motion at a site due to known and suspected earthquake sources. The disadvantage of PSHA is that the concept of a “design earthquake” is lost; i.e. there is no single event that for design or retrofit. The relative contributions of the various sources to the total seismic hazard are determined as a function of their occurrence rates and their ground-motion potential. This study describes a method wherein a design earthquake can be obtained that accurately represents the uniform Fourier hazard spectrum from a PSHA. Seismic hazard can be deaggregated to show the contribution by magnitude, distance and ground motion uncertainty.
