Earthquake Action Determination for Seismic Assessment of Existing Structures

In order to study earthquake actions when assessing seismic performances of existing structures,a new three-level seismic assessment criterion is presented based on performance-based seismic design.According to Poisson model,the return period of moderate-minor,moderate and major earthquake in different re-service periods are calculated based on equal exceeding probability principle.The relations of earthquake intensities,seismic influence coefficients,and ground seismic accelerations are presented with the reference of the latest research findings of earthquake hazard analysis.By modifying the seismic design reference period,the application of equal exceeding probability principle can be extended to taking into account the important factors of different existing structures.It can be used for performance-based seismic assessment and strengthening of existing structures.