Tangshan 1976 earthquake: Modelling of the SH-wave motion in the area of Xiji-Langfu

摘要

The reasons for the anomalous high macroseismic intensity caused in the Xiji-Langfu area by the Tangshan, 1976 earthquake can be found in its special geological conditions. This area is formed of deep deposits beside the Xiadian fault, that consist mainly of alluvium sands and clays, which are poorly consolidated with high water content. Resonances, excitation of local surface waves and their propagation cause strong amplifications and long durations of signals. Based on simulated strong ground motion, we have computed quantities commonly used for engineering purposes: the maximum amplitude (AMAX) and the total energy of ground motion (W), which is related to the Arias Intensity. This computational result can be used to explain the large macroseismic intensity observed in the Xiji-Langfu area, in connection with the Tangshan earthquake. (author). 18 refs, 15 figs, 2 tabs. (Atomindex citation 26:069447)