西藏某水电站高边坡地震永久位移分析

Analysis of seismic permanent displacement of a high slope for a hydropower plant in Tibet

西藏某水电站位于喜马拉雅地震带和藏中地震带交汇处,岸坡陡峭,坝址区某高边坡对枢纽工程的安全影响最大。为尽快消除该边坡的安全隐患,本文基于Slide软件选用了3条不同类型的地震波,采用Newmark滑块分析方法计算了该边坡在不同地震峰值加速度作用下的动力反应和永久位移,并采用拟静力法对该边坡在设计地震动作用下的稳定性进行了验算。计算结果表明,在设计地震动作用下该边坡是稳定的,随着地震波幅值的增加该边坡产生的总滑移量也在不断的增加;对于不同类型的地震波,虽然输入的地震峰值加速度相同,但地震动参数的差异会影响边坡产生的永久位移。研究结果可为工程单位进行类似边坡工程稳定性分析提供参考依据。

A hydropower plant in Tibet is located at the intersection of the Himalayan seismic belt and Central Tibet seismic belt,with a steep bank slope. A high slope in the dam site area has the greatest im pact on the safety of the pivotal project. In order to eliminate the safety hazard of the slope as soon as pos sible,this paper selects three different types of seismic waves based on Slide software,and calculates the dynamic response and permanent displacement of the slope under the action of different seismic amplitudes by using Newmark sliding block analysis. The pseudostatic method is used to check the stability of the slope under the design ground motion. The calculated results show that the slope is stable under the effect of designed ground motion,and the total slip generated by the slope increases with the increase of seismic wave amplitude. For different types of seismic waves, when the input peak seismic acceleration is the same,the difference in ground motion parameters will affect the permanent displacement of the slope. The research results can provide reference for similar slope engineering stability analysis.