边坡临界滑动面与临界可靠度滑动面对比分析

针对2个典型均质土坡,采用不平衡推力法计算滑动面的安全系数,从而构建了边坡可靠度分析的功能函数,随机产生一系列潜在可行滑动面;假定了不同的强度变异参数,分别利用蒙特卡罗法计算其可靠度指标,并与其确定性分析的安全系数进行了对比.研究结果表明：当滑动面的安全系数与其可靠度指标存在显著的单调对应关系时,临界滑动面与临界可靠度滑动面基本重合;而当两者之间不存在显著的单调对应关系时,临界滑动面与临界可靠度滑动面存在显著区别,对于均质土坡,两者的可靠度指标相差10%左右,而对于两层土坡而言,二者的可靠度指标相差高达70%.

Comparative analysis between critical slip surface and critical reliability slip surface of slopes

The unbalanced thrust force method was adopted to calculate the factor of safety for given circular slip surface thereby defining the performance function in reliability analysis.A series of potential slip surfaces were randomly generated and their reliability indexes by Monte Carlo method and factors of safety by unbalanced thrust force method were obtained respectively.The curves between factors of safety and reliability indexes were provided.The comparative research shows that the critical slip surface is identical with critical reliability slip surface if the curve is considerably monotonous;otherwise,the considerable difference between critical slip surface and critical reliability slip surface is noticed.The deviation can be up to approximate 10% for homogeneous soil slope and up to 70% for soil slopes containing two soil layers.