某水电站左岸B20崩塌堆积体稳定性研究

对金沙江某水电站左岸B20崩塌堆积体处的工程地质条件进行分析,并对下部凝灰岩夹层的分布形式及特点进行重点研究,提出B20崩塌堆积体可能的滑移方式,运用有限元方法和极限平衡理论方法对其在不同可能工况下的稳定性进行分析。有限元计算结果表明,B20崩塌堆积体沿基岩和崩塌堆积体接触面上的滑动面组合形式的安全系数能够满足工程要求;地震作用对崩塌堆积体的影响较大,但引起边坡失稳的可能性小。采用极限平衡方法计算了不同工况下B20崩塌堆积体沿崩塌体内部产生局部圆弧滑动的可能性,计算结果表明各工况的安全系数均能满足工程安全的需要。根据综合分析结果,提出B20崩塌堆积体处理建议。

Stability study on falling accumulation B20 on left bank of hydropower station

The geological conditions of the falling accumulation B20 on the left bank of a hydropower station on the Jinsha River are analyzed.The distribution forms and features of the tuff interlayer are mainly studied. The probable slide modes of the falling accumulation B20 are proposed.The finite element method(FEM) and limit equilibrium theory are used to analyze the stability of falling accumulation B20 in different conditions.The results of the FEM show that the safety factor along the contact surface between bedrock and the falling accumulation satisfies the engineering demands,and earthquakes have a major influence on the falling accumulation B20,but with less possibility of instability.The limit equilibrium theory was used to analyze the local stability of falling accumulation B20 in different conditions.The results show that the factor of safety can satisfy the engineering security demands.According to comprehensive analysis of the results,treatment suggestions for falling accumulation B20 are proposed.