Probabilistic Seismic Hazard Assessment without Source Characterization

Abstract

Conventional Probabilistic Seismic Hazard Assessment (PSHA) is difficult to apply in regions lacking sufficient information of the geological setting, active faults, and so forth. Also, for a site-specific PSHA, site effects arising from both crustal rock and overlying soil sediments are generally not assessed rigorously. This is of particular importance for those metropolitan cities having a significant proportion of reclaimed land, because the site-to-site variability of such site effects can be very large. The objective of this paper is to demonstrate an alternative procedure for constructing site-specific uniform hazard spectra (UHS), extended from a recently-developed Direct Amplitude-Based (DAB) approach. The method has a number of important advantages compared with conventional PSHA. Using the proposed approach, response spectral values have been computed for the whole period range of engineering interest, to form a set of site-specific UHS.