土体抗剪强度指标变异水平对边坡稳定安全系数取值的影响

针对传统的边坡稳定极限平衡方法不能考虑土体抗剪强度指标变异性影响的问题，基于极限状态的概率分析原理，采用Monte-Carlo法对均质路堤边坡的稳定性开展了可靠度计算，讨论了稳定安全系数一定的条件下边坡失效概率随土体抗剪强度指标变异水平的变化规律，分析了安全系数与边坡可靠指标的对应关系及其随土体抗剪强度指标变异水平的变化特征。研究表明：边坡可靠度受土体抗剪强度指标变异性影响显著，呈现出随土体抗剪强度指标变异水平提高而急剧减小的趋势；为保证边坡具有相同的可靠性，安全系数的取值应与土体抗剪强度指标的变异性相适应，据此提出了基于可靠指标和土体抗剪强度指标变异水平的安全系数取值原则及其对应的三参数函数关系式。

Influence of variation levels of soil strength indexes on the value of slope stability safety factor

Traditional limit equilibrium methods of slope stability fails to consider the influence of soil strength indexes variability. Based on probability analysis principle of limit state, Monte-Carlo method is used to calculate the reliability of stability of homogeneous embankment slope. And with constant safety coefficient, changes of slope failure possibility with different levels of soil strength indexes are studied. The corresponding relationship between safety coefficient and reliability index of the slope and changes of safety factor with variation levels of soil strength indexes are analyzed. Results show that: the slope reliability is affected by soil strength indexes variability significantly, indicating sharp decreases with increase of soil strength indexes variation levels; in order to get the slope the identical reliability, safety coefficient should be changed according to soil strength indexes variability. The safety coefficient should be changed according to reliability index and soil strength indexes variation levels and based on which three parameters function is put forward.