滑坡稳定性分析与安全系数取值研究

在地质灾害中,滑坡灾害分布最广、发生频率最高、危害最大,是我国地质灾害防治的主要对象。滑坡研究的主要任务之一是稳定性分析。论文针对三板溪水电站进水口滑坡和水布垭水电站大岩淌滑坡,分别采用刚体极限平衡法、块体单元法、有限单元法对稳定安全系数和条间推力分布曲线进行分析和比较,研究各种方法的差异和计算精度,以及各种方法稳定安全系数的取值标准,希望为水利水电工程边坡设计规范有关有限单元法、块体单元法条目的编写和相应的允许安全系数取值标准的制定提供一定的参考。研究结果表明:①块体单元法计算的安全系数与刚体极限平衡法计算的安全系数可以采用相同的取值标准,而有限单元法计算的安全系数取值标准可适当降低;②块体单元法计算的条间水平推力、条间剪切力与刚体极限平衡法(尤其是Sarma法)计算的条间水平推力、条间剪切力非常相近,有限单元法计算的条间水平推力、条间剪切力较小;③分析方法、力学模型与参数取值应与安全系数取值标准相匹配。

Study of stability analysis and safety factor of landslide

Landslide is one kinds of geological hazards,which distributes widely,occurs with high frequency,and causes great losses in life and properties.One of the main tasks in landslide study is slope stability analysis.In this paper,limit equilibrium method of rigid body,block element method,and finite element method are used to analyze the stability of the intake landslide at Sanbanxi hydroelectric station and Dayantang landslide at Shuibuya hydroelectric station.The factor of the safety,horizontal thrust distribution curve between slices, as well as the calculation accuracies of the three methods are compared.The permissible factors of safety using the three methods are also discussed.The study is intended to provide a reference for the slope design code of hydropower engineering projects regarding to finite element and block element methods.The results of the study show that:(1) The permissible factor of safety using block element method is similar to limit equilibrium method of rigid body,while that using finite element method is smallest;(2) The horizontal thrust and shear stress between slices of block element method is very similar to that of limit equilibrium method of rigid body(especially Sarma Method),while the result of finite element method is smaller;(3) The method,the mechanical model and the parameters should be matched with the permissible safety factor.