Probabilistic Seismic Hazard Analysis for Low Seismicity Region

摘要

Critical facilities and structures such as nuclear and thermal power plants and dams, as well as the siting of new industry, require design ground motion data which are as accurate, homogeneous and complete as possible, so that hidden tectonic features may be revealed and seismic hazard assessed. Seismic hazard analysis is usually performed to obtain a characterization of the earthquake ground motion and liquefaction at a particular site. However, main interest is in the estimation of ground motion hazard, since it causes the largest economic loss in most earthquakes. Thus, the seismic hazard studies are carried out for estimating ground motion parameters expected to occur at bedrock levels at a particular site during strong earthquakes. Design earthquake selection process involves consideration of the seismic hazard at the site and the general response characteristics of the structure being analyzed considering the local site effects. Seismic hazard is commonly used to describe the severity of ground motion at a particular site without consideration of the consequences. In most situations the seismic hazard is uncertain, and is posed by the possible occurrence of earthquakes at more than one location; likewise, the sizes, or magnitudes of potentially damaging earthquakes. It is to be noted that the distance and magnitude of the causative fault have more effect on the nature of strong motion expected at a specific site. The methodologies for earthquake hazard analysis during the last few decades were developed primarily to assess seismic hazards of tectonically active areas (Cornell 1968; Der Kiureghian and Ang 1977; Wesnousky et al. 1984; McGuire 1995; Main 1995; Peter Tsai 2000; Rebez and Slejko 2000).