Deterministic seismic hazard analysis considering non-controlling seismic sources and time factors

Deterministic seismic hazard analysis (DSHA) is an approach for evaluating site-specific seismic hazard that is influenced by the maximum hazard from the controlling sources affecting the specific study site. In its conventional form, DSHA does not consider sources other than the largest "controlling" source and it does not account for the time factors owing to the uncertainty of earthquakes occurrences in time. Under certain condition, ignoring these factors can lower the conservatism of the hazard estimate, especially when other non-controlling sources generate hazards nearly equivalent to that of the controlling source or when the structure's design life is longer than the controlling source earthquake's return period. This study discusses several limitations of conventional DSHA and provides a modified approach for DSHA which we believe should supplement the conventional method. An example is presented to demonstrate how conventional DSHA can be un-conservative for certain problem types.