岩体隧道蠕变效应的有限元分析

Creep Finite Element Analysis of the Rock Tunnel

对岩体隧道的长期观察和量测表明，许多在成洞之初的岩体，由于蠕变变形随时间不断发展，经过一段时日以后，围岩体可能会发生失稳或坍塌破坏。传统的弹性或弹塑性理论，无法考虑变形的时间因素。选用流变理论中能很好反映岩体应力应变随时间变化的广义开尔文模型，结合某岩体隧道的实例，利用有限元分析软件ANSYS模拟了岩体隧道开挖后围岩蠕变的全过程。模拟的结果使人们能够方便地掌握岩体隧道各个部位在不同时刻的变形量和蠕变率。对岩体隧道的设计和施工有一定的指导意义。

Long - term observation and measurement to rock mass tunnels indicates that a great deal of rock mass is subjected to a slow time - dependent movement at the beginning of excavation . With their continuation, these movements could damage the tunnel of the rock mass, leading to possible instability and collapse. Conventional techniques such as elastic or elastoplastic theory cannot solve this time - dependent problem. In order to answer this question, this paper uses the generalized Kelvin model which is based on the rheology constitutive laws to simulate the whole process of tunnel creep through a rock mass tunnel instance by finite element analysis software ANSYS. The result of numerical analysis provides the best approach to understanding the deformation and creep ratio in any particular location of the tunnel at any time. The conclusion that can be reached from this example has guidance to a certain extent in the designing and construction.