水库蓄水及其邻区应力分布

THE RESERVOIR IN STORE AND STRESS DISTRIBUTION NEAR AREA

本文以密云邓家湾的实际应力测量结果,讨论了水库蓄水对邻区应力分布的影响,指出水库蓄水使其邻区垂直于库岸方向的水平应力值增加,其数值大于水压应力场的影响。水库邻区的断层若与库岸平行,则水库蓄水使作用在断层面上的法向应力增加,邻区的稳定性增高;反之,则会导致邻区的不稳定。水库蓄水对邻区的附加侧应力作用是水库蓄水诱发地震的重要原因。

By means of data measuring stress at the Deng jiawan area of Mi—yun reservoir We discuss influence of the reservoir storing water on stress distribution near region. The results show that storing water in reservoir increases norizontal stress of surrounding area in the direction which is perpendicular to bank. the effect will increase normal stress of fault surface which is parallel to bank of reservoir. Thus the fault is stable whereas unstable for fault to be vertical to bank. It is key cause of reservoir earthquake resulting from storing water.