4. Map time into Seismic Intensity
ET analysis is based on the application of intensifying dynamic excitations. Analysis time is associated with excitation intensity in ET analysis. However, for the matter of presentation of the analysis results, time is not a convenient indicative of intensity. Usually, it is better to map time into a more sensible seismic intensity or risk measure such as PGA, or Hazard Return Period. There are various ways to carry out this transformation of variables. It is intended to represent the best practices in this regard here.
Proposed methods for mapping time in ET analysis into PGA and Hazard Return Period is explained in the following sections.