Finite Fault Modeling of Strong Ground Motions Using a Hybrid Deterministic-Stochastic Approach

摘要

A hybrid deterministic-stochastic method (DSM) is developed to calculate synthetic time series of ground accelerations radiated from an extended source. The main goal of the proposed methodology is to include in the classical point-source stochastic method (PSSM) the effects of the rupture propagation on a finite fault. This purpose is achieved through two important modifications of the PSSM technique. First, the envelope does not have a predetermined functional form; rather, it is calculated deterministically following the isochron formulation with a kinematic rupture model. Second, we have generalized the various parameters of the point-source ground motion spectrum to account for the extended fault: corner frequency, distance from the fault, and radiation pattern are evaluated through the kinematic modeling. The guiding principal in all these modifications has been to develop a robust methodology capable of capturing the complexity of near-source ground motion even when input information about earthquake source, propagation medium, and site characteristics are of a very schematic nature.