VARIANCE-BASED SENSITIVITY ANALYSIS ON PSHA

Probabilistic Seismic Hazard Analysis (PSHA) was commonly used in the past decade for developing site-specific earthquake-resistant designs. PSHA is a function-of-random-variable calculation in which earthquake magnitude, source-to-site distance, and the error term of Ground Motion Prediction Equation (GMPE) are the three random variables considered in the analysis. This paper introduces the first series of Variance-Based Sensitivity Analysis on PSHA, quantifying the sensitivity for the three variables. It shows that GMPE (or GMPE’s error term) plays the most crucial role in PSHA, or the result of PSHA is most susceptible to GMPE. Given that its sensitivity was as high as 76% (24% for the other two parameters combined), new strategies for conducting a PSHA project more effectively were also proposed in this paper.