Synthesis of strong ground motions at two rock stations during the great Wenchuan earthquake from a hybrid source model

In order to study the characteristics of ground motions at the two dam sites damaged during the great Wenchuan earthquake in 2008, the motions at two observation stations nearby are synthesized in this paper. 30 finite fault based hybrid source models of the great Wenchuan earthquake with magnitude 8.0 is built. The global and local parameters are both generated from the truncated Normal distribution with mean and standard deviation values estimated by a set of semi-experiential calibration laws and from the regional seismo-tectonics, structure of the crust, and seismicity. A representative source model is then chosen from the corresponding response spectrum mostly close to the average one. The result motions are presented, and the characteristics of the time histories, response spectra and the peak accelerations are quite close to the recordings.