隧道地层变位的可靠性分析

分析了隧道与围岩设计中的不确定性因素 ,指出由于隧道及岩土参数分布的随机性 ,地层变位具有不确定性。运用ANSYS有限元程序建立隧道地层变位的计算模型 ,进行数值模拟并取得地层变位的原始数据。在此基础上把主要影响因素视为随机输入变量 ,地层变位为随机输出变量 ,采用蒙特卡洛方法模拟出地层位移的统计值 ,进而计算出地层变位的可靠指标与失效概率 ,并通过相关系数矩阵和概率灵敏度图分析了随机输入参数对地层变位的影响 ,为隧道地层变位的可靠性分析提供了一种新的途径。

Reliability Analysis of Stratum Displacement around the Tunnel

The undetermined factors in design of tunnel and surrounding rock were analyzed. Due to the stochastic property of parameter distribution of the tunnel and surrounding rock, the stratum displacement was also undetermined. By means of ANSYS program, FEM model was built and original data of stratum displacement were obtained. Based on this model, the main affecting factors were taken as stochastic input variables and the stratum displacement as stochastic output variables. The statistic values of vertical and horizontal displacements were simulated by Monte Carlo method, and then the failure probability and reliability index of stratum displacement were calculated. Finally the influence of stochastic input variables on vertical and horizontal stratum displacement was analyzed by correlated coefficient matrix and sensitivity plots. The method would provide a new way for reliability analysis of the stratum displacement.