中文摘要：

提出了一种基于移动最小二乘法（MLSM）的隧道开挖可靠度分析方法，该方法利用MLSM构建功能函数的代理模型，解决了实际工程中功能函数需借助数值方法求解的问题；通过均匀设计构造MLSM函数，在此基础上，采用一阶可靠度方法（FORM）计算不同极限状态的可靠度指标和失效概率．以一个存在3种不同失效模式的隧道开挖支护稳定问题为例，通过与多项式响应面法和直接FORM法比较，验证了该方法的精度和效率．讨论了不同失效模式下参数的敏感性以及隧道支护安装位置和参数相关性对不同模式下隧道失效概率的影响规律．

英文摘要：

A reliability analysis procedure is proposed for tunnel excavation problems based on the moving least squares method （MLSM）. The MLSM is employed herein as a surrogate model to approximate the actual performance functions which are always of implicit form in most of the practical applications. The MLSM function is constructed using sampling points generated via the uniform design method. Based on the obtained MLSM model, the reliability index and its corresponding failure probability are calculated with first-order reliability method （FORM）. The accuracy and efficiency of the proposed approach are illustrated with an illustrative example of three different failure modes. The results are also compared with the polynomial response surface method （RSM） and the direct FORM. Sensitivity analysis and the influ- ence of the support installation position and the correlation of random variables on the generated failure probabilities of different failure modes are investigated.