寒区隧道衬砌结构可靠性分析

为了研究寒区隧道在运营阶段衬砌结构的可靠性,考虑到冻胀力、围岩压力和结构自重应力对围岩衬砌结构的影响,以昆仑山寒区隧道工程为背景,采用ANSYS中的PDS(概率设计)模块和蒙特卡洛拉丁超立方抽样方法,对影响寒区隧道衬砌结构可靠性的主要因素以及保证隧道结构安全的可靠性指标进行研究。结果表明:基于ANSYS数值模拟,通过研究冻土围岩温度场和应力场的耦合结果,得到冻胀对衬砌结构产生的最不利的位置;以概率论和数理统计相结合的方式,对衬砌结构最不利位置的可靠性进行定性和定量的分析,得到衬砌结构的可靠性指标;蒙特卡洛法中的拉丁超立方抽样提高了抽样概率的精确性,概率设计的敏感性和设计变量之间的散点图分析,有利于确定影响衬砌结构可靠性的主控因素,进而针对可控因素采取措施,以此提高衬砌结构的可靠性。

Reliability Analysis of Tunnel Lining Structures in Cold Region

In order to ensure the reliability of tunnel lining structures in cold region during the operational phase,PDS(probability design) module and Monte Carlo Lad in super cube sampling method in ANSYS are employed to study the main factors affecting the reliability of the lining structure and the reliability index based on the Kunlun Mountains tunnel project and with a view to the influence of frost heaving force,surrounding rock pressure and the weight of the structure stress on surrounding rock lining structure. The results show that based on ANSYS numerical simulation,the most unfavorable position of lining structure caused by the frozen expansion is identified through the analysis of frozen surrounding rock temperature field and stress field coupled results; with probability theory and mathematical statistics,the reliability of the most disadvantageous position of the lining structure is analyzedin perspective of qualitative and quantitative,and the reliability index of lining structure is obtained;Latin hypercube sampling of the Monte Carlo method improves the accuracy of sampling probability,and the analysis of the sensitivity of the probability design and the scatter plot between design variables contribute to the determination of the reliability of tunnel lining structure of main control factors. And take measures against controllable factors and then to take measures to improve the reliability of tunnel lining structure.