汶川地震中塔藏断裂对地震动的影响研究

Effects of Tazang Fault on Ground Motion during Wenchuan Earthquake

地震动的频谱特征与地震波传播过程中所经过的构造环境有密切的联系,并且随着强震动记录的积累,非发震断裂构造可能会对强震动记录的特征产生复杂的影响。以汶川地震中塔藏断裂周边数字强震动台站(永丰、勿角、郭元、白河)所获取的加速度记录为依据,基于研究区的区域地质构造特征,通过频谱分析等手段来研究非发震断裂对地震动的影响。分析得到了塔藏断裂对地震动影响的规律,研究表明非发震断裂对于地震动具有一定的隔震作用,断层破碎带场地对地震动具有一定的放大作用。

The spectrum features of strong ground motion are closely connected with the structural settings through which seismic waves travel.With the accumulations of strong ground motion records,there is a general realization that non-causative fault may exert complex effects on the features of ground motion.Based on the acceleration time records of the Wenchuan earthquake recorded by the observation stations(Yongfeng,Wujiao,Guoyuan,Baihe)on both sides of Tazang fault,and taking into account the regional tectonics features,we studied the effects of non-causative fault on ground motion by means of spectrum analysis.Through analysis,we also figured out the regular effects of Tazang fault on ground motion.As the research shows,non-causative fault has some isolation effect on ground motion,and fault fracture zone has an amplification effect on ground motion.These results can provide a reference for researches on ground motion effect,intensity fast report and early warning,and near-field strong ground motion simulations.