STUDYING THE IMPORTANT PARAMETERS IN EARTHQUAKE SIMULATION BASED ON STOCHASTIC FINITE FAULT MODELING

摘要

Opposite to the long period ground motions that can be predicted and estimated, high frequency ground motions have random quality and behave stochastically. Bore stochastic method can be used for modeling high frequency ground motions where there is no accelerograghic record. Stochastic modeling methods are of two kinds: in the first one, seismic source is a point source and in the second, named modeling based on finite fault,seismic source is a rectangular fault plane divided by the same point sources in its longitudinal and traversal directions. Three parameters- quality factor, kappa and stress drop, the important parameters in modeling, are considered in this study. Here, it is found that the main effect of quality factor is on the high frequencies and variation of this parameter has no significant effect on the spectral accelerations in low frequencies. The spectral acceleration and maximum ground acceleration (PGA) decrease when kappa increases; however, the acceleration reduction is higher in high frequencies. Finally, the stress drop increment makes the spectral acceleration increase significantly in high frequencies. In this research the effect of shear wave velocity and density on the modeled accelerations are studied as well.