【摘要】 汶川地震的发生与其附近的紫坪铺水库是否有关是一个引起国际关注的问题.考虑水库的实际形状和蓄水深度,使用半无限空间的解析解,分析讨论了水库蓄水和放水过程对周围区域断层稳定性的影响.结果表明,对于倾角较小的断层面,水库放水使库区下方近地表的库仑应力有明显增加,增量达到0.2MPa,远离水库区域的库仑应力呈现象限性特征,而且随着距离的增加迅速减小.汶川地震震源落在蓄水时库仑应力减小、放水时库仑应力增加的区域内,但由于距离水库较远的原因,汶川地震前放水时库仑应力的增量只有0.005MPa左右.更多还原

【Abstract】 Whether the Zipingpu reservoir triggered the 5.12 earthquake has attracted international attention.We discuss influences of the artificial load on stability of faults in the vicinity based on the solution of Boussinesq’s problem with the consideration of geometry of the reservoir and real water depth.The results indicate that the static Coulomb stress changes obviously near the surface and its magnitude can be 0.2MPa,but decreases rapidly with distance.The seismic source of the 5.12 earthquake was in the field where the static Coulomb stress changes are positive.However,the magnitude of about 0.005MPa is too small because of the remoteness from the reservoir.We also discuss the distribution of the static Coulomb stress caused by point load on some typical faults.更多还原