DISPLACEMENT MODELLING OF INTRAPLATE EARTHQUAKES

This paper presents the case for a displacement-based approach for the seismic design and performance assessment of structures in intraplate regions. A newly established model for predicting seismic displacement demand is introduced. The presented material is based on outcomes from research which integrates expertise in the fields of engineering seismology, soil dynamics, structural dynamics and structural engineering. The analysis of a theoretical fault-slip function predicts peak displacement demand (in millimeters) equal to 510M − at 30 km hypocentral distance in “hard rock ” conditions, where M is the moment magnitude of the earthquake. Significantly, the theoretical predictions have been shown to be highly consistent with predictions by both stochastic and empirical models which were developed from recorded ground motions. The effects of crustal modifications, attenuation, and site amplification are taken into account by component factors. Expressions for each of these factors are summarised in the table at the end of the paper and illustrated with a worked example in Appendix A to facilitate their practical applications