基于验算点法的地震力作用下边坡可靠性分析

Reliability Analysis of Slope Under Seismic Load Based on Checking Point Method

为了给地震力作用下滇西南地区高边坡稳定性分析提供一种切实可行的可靠性分析方法，针对地震力作用下影响边坡可靠性计算的主要变量（主要考虑地震力的随机性和不确定性、边坡岩土体抗剪强度参数的不确定性），并全面考虑变量的实际分布规律和变量之间的相互关系，采用传递系数法建立引入地震力作用的边坡极限状态方程，再采用验算点法对极限状态方程进行求解，对其中非正态变量进行当量正态化处理。通过对极限状态方程的求解和分析，得出地震力作用对边坡可靠性指标的具体影响程度、滇西南地区高边坡可靠性指标、破坏概率分别与地震力之间的关系、地震力作用下影响边坡可靠性的主要变量的分布规律。结果表明：地震力的作用对边坡的可靠性指标影响显著，地震力作用下的可靠性指标相比于无地震力作用下减少了50％～97％；滇西南地区边坡稳定的可靠性指标随着地震力的增大而减小，破坏概率随着地震力的增大而增大；不同地震烈度下的水平地震峰值加速度均近似服从极值I型分布，抗剪强度参数均近似服从正态分布，且抗剪强度参数之间具有一定的相关性。

In order to provide a feasible reliability analysis method for the stability analysis of high slope under the seismic force in southwest Yunnan, aimed at the main variables affecting the reliability calculation of slope under seismic force, the randomness and uncertainty of the seismic force, and the uncertainty of shear strength parameters of rock and soil mass were mainly considered. And to fully consider the actual distribution laws of variables and the relationships among variables, the transfer coefficient method was used to establish the limit state equation of slope by introducing the action of seismic force, and then the limit state equation was solved by the checking point method, and the non-normal variables were dealt with the equivalent normal treatment. By solving and analyzing the limit state equation, the effect of seismic force on the reliability index of the slope, the relationship between the high slope stability reliability index and seismic force, the relationship between the failure probability and the seismic force, and the distribution law of the main influence factors of the slope reliability under the action of seismic load were obtained. The results show that the impact of seismic force on the reliability index of the slope is very huge, and reliability index under the action of seismic force decreases by 50%- 97% compared with that without the action of seismic force; the reliability index of the slope decreases with the increase of the seismic force, and the failure probability increases with the increase of the seismic force; peak value of horizontal earthquake acceleration approximates to the extreme I type distribution under different earthquake intensities, and the shear strength parameters are both approximation to the normal distribution, and have certain correlations.