复合式衬砌在围岩蠕变过程中的受力规律研究

Study on mechanical rules of double-lining in creeping surrounding rock

摘要: 为了分析隧道复合式衬砌在围岩蠕变过程中的受力规律,利用有限元程序ANSYS建立计算模型,采用广义开尔文本构关系,分别分析了二次衬砌在不同支护时机和不同刚度下,复合式衬砌的受力规律。分析结果表明:在不同的时机施加二衬,其受力都有一个逐步增大并趋于稳定的过程,初支与二衬受力随二衬支护时机的变化趋势是相反的;二衬支护越早,其受力越大。通过早施作二衬,来转移初支上的应力是不合适的。当二衬刚度增加时,其所分担的围岩压力将增大,而初支分担的围岩压力有一定的减小。结合云腾岭隧道进行具体分析,得出该隧道二次衬砌的最佳支护时间为开挖后第40天。另外,通过对该隧道现场监控量测分析发现,二衬的受力—历时曲线与有限元分析相吻合。

Abstract: In order to analyze the mechanical rules of double-lining in creeping surrounding rock tunnel,a finite element model is established based on the finite element program ANSYS. Using generalized Kelvin constitutive relation,the mechanical rules of double-lining are analyzed when secondary lining is applied at different support time or different stiffness. The analysis results indicate that the stress of secondary lining increases gradually,and then tends to be stable when it is applied at differen...