UNCERTAINTIES IN SEISMIC RISK PROCEDURES

Probabilistic and statistical methods are being more widely used in seismic risk analyses. These procedures allow the maximum usage of geologic and seismological input into the evaluation of probable risk levels expected at a site. The seismic parameters used in an analysis must be based upon as complete and accurate a data set as possible and the relationships derived from the data must be consistent and representative of that data base. Several case histories are presented. Each one demonstrates some of the difficulties inherent in most data sets and the methods available to overcome them.