弱层台阶边坡可靠度非侵入式随机分析

Non-intrusive random analysis on reliability of weak layers bench slope

为确保复杂结构边坡的安全稳定,针对弱层台阶边坡可靠性开展非侵入式随机分析。以抗剪参数为随机变量,采用局部平均法进行随机场离散,采用随机场和Monte-Carlo(SMC)法编制程序进行数值计算,并与Monte-Carlo(MC)法结果进行比较。结果表明:利用非侵入式随机分析方法计算可靠度效率更高且易于实现;随机场可以反映岩体力学参数的空间变异性以及参数之间相关特性,更接近于实际情况,弱层对边坡稳定性有重要影响,会导致边坡安全系数降低,且最大位移会显著增大;采用MC法会过度放大边坡的失效概率,而SMC法得到的结果更可靠。该结论可为复杂结构边坡的可靠性分析提供参考。

In order to determine the safety and stability of slope with complex structure more accurately,the reliability of weak layers bench slope was analyzed by using the non-intrusive random analysis method.The shear parameters were taken as the random variables,and the local average method was used for the discretion of random field.The numerical calculation was realized by programming the program with the random field&Monte-Carlo method(SMC),and the results were compared with the results of Monte-Carlo method(MC).It showed that the non-intrusive random analysis method had high efficiency of calculating the reliability,and it was easy to be realized.The random filed could reflect the spatial variability of the mechanical parameters of rock mass and the cross-correlation characteristics between the parameters,which was closer to the actual conditons.The weak layers had important influence on the stability of slope,which would cause the decrease of the safety factor of slope,and the maximum displacement would increase remarkably.The failure probability of slope calculated by the MC method was overestimated,and the results obtained by the SMC method was more reliable.The results have reference significance for the reliability analysis of slope with complex structure.