Analysis for site seismic hazard probability considering the orientation distribution of potential seismic sources

The assessment of the intensity of seismic impacts on a site by the classical method is the scalar sum of the seismic impacts caused by potential seismic sources in all orientations within the earthquake influence area around the site, not only overestimating the intensity of seismic ground motion of the site but also failing to consider the difference in the seismic impact modes and directions caused by the seismic waves with different incident directions. Based on the analysis framework consisting number of seismic sources, magnitude grades, and distance ring domains in the classical method, azimuth sectors are further added, thus forming an improved seismic hazard analysis method considering the orientation distribution of potential seismic sources. The improved method was applied in Baoji area, China. The analysis results of the improved method can provide multiple sets of seismic impact evaluation parameters caused by the seismic sources in different orientations, and each set of parameters corresponds to the seismic impacts of potential seismic sources in one of azimuth sectors around the site. What’s more, the improved analysis method lays a foundation for clarifying the directions of seismic actions on a site, and significantly improves the overestimation of the site seismic action intensity by the classical method. The improved method takes the effect of potential seismic source orientation on site seismic actions into account, and provides the possibility for engineering earthquake resistance to consider earthquake damage modes.