Seismic reliability evaluation of structural systems for different soil conditions

This article describes how the seismic design of a structure considering soil conditions is a very difficult and complicated process. In order to minimize economic cost following an earthquake, the performance-based seismic design (PBSD) concept is proposed. This lets engineers design structures by considering a predefined amount of damage the stakeholders are willing to accept and the corresponding economic consequences. Three performance levels; Immediate Occupancy (IO), Life Safety (LS), and Collapse Prevention (CP) are being considered at present. The major challenge in implementing PBSD is the estimation of the underlying risk. To fill this knowledge gap, a novel reliability approach is proposed by integrating first-order reliability method, response surface method, and advanced factorial concepts. PBSD is showcased with the help of a structure designed by experts satisfying recent design requirements. The results indicate that PBSD guidelines are more desirable than the older criteria, structures should be designed considering multiple earthquake time histories, and soil condition is an important design factor.