水库断层岩溶带地震波波速比研究

Study on wave velocity ratio of fault karst zone of reservoir

采用固定台站法计算了三峡水库蓄水期间,高桥断层附近断层岩溶地区记录到的ML2.0以上地震的波速比,并对研究区内沿断裂带及透水性不同地层的内波速比值等进行对比分析。结果表明,断层岩溶带地区受库水影响,波速比值偏高,波速比与不同地层岩石的透水性成正比,断层岩溶带地区孕育较大水库地震的可能性不大。

During the impoundment of Three Gorges Reservoir,the fixed-station method is applied to calculate the wave velocity ratio of recorded reservoir-induced earthquakes above ML2.0 in fault karst zone areas near the Gaoqiao fault.Furthermore,the contrastive analysis on wave velocity ratio along the fault zone and within the different permeability rock strata is carried out.The result shows that,affected by water in the reservoir,the value of wave velocity ratio in fault karst zone area is higher,and the wave velocity ratio is proportional to permeability of rocks in different strata.And we conclude that the possibility for the development of larger reservoir-induced earthquakes in fault karst zone areas is lower.