参数随机性对公路边坡结构安全指标的影响分析

利用概率理论和随机摄动理论研究了土体粘聚力、摩擦系数和重度随机变化时对边坡结构安全系数和可靠指标的影响规律。结果发现,随着这三个参数变异性的增大,安全系数具有线性变化规律,且摩擦系数的变异性对安全系数的影响最大,粘聚力次之,重度最小;而可靠指标却具有先陡降后缓降的变化趋势,且粘聚力和摩擦系数向负方向扰动时对可靠指标的影响比其向正方向扰动时大,但重度对可靠指标的影响规律与前者相反。

The effect of three parameters, i. e. , the cohesive force, the friction coefficient, random variance of gravity to the safety index for slope structure is discussed with the random, perturbation theories. It has been proven that the safety factor has a linear change law with the increase in variability of these parameters. Of them, the variability of friction coefficient has the biggest to the safety factor, the second is the cohesive force, and the smallest is the degree of gravity. On the other hand, the reliability index shows the variable law failing suddenly at first and then descending slowly, which is influenced greatly by their negative variance the cohesive force and the friction coefficient more than that in their positive variance.