考虑流变特性的隧道围岩变形效应分析

为了探讨考虑流变效应情况下隧道围岩和衬砌的变形情况,从而进一步确定隧道的合理衬砌时机。首先,分析围岩的流变特性对隧道变形和衬砌抗力的影响,通过理论推导得到了同时考虑黏弹塑性的隧道围岩变形计算公式,该公式包含时间参数,可确定达到不同衬砌位移及围岩位移所需要的时间。然后,以南龙铁路隧道工程为背景,针对隧道拱顶下沉、周边收敛、围岩压力和初衬内力,开展隧道二衬合理支护时机的监测分析,得到围岩变形计算公式中的待定系数,并确定隧道衬砌的合理支护时机。将得到的结果与现场监测的结果进行对比,发现二者得到的二衬支护时机基本相同,从而验证计算结果的正确性。

Deformation Analysis of Surrounding Rock Mass of Tunnel under Rheological Effect

To study the deformation of surrounding rock mass and lining of tunnel under rheological effect and further determine proper lining time,the effect of rock rheological characteristic on the deformation and lining anti-force is analyzed,and the calculation formula of the deformation of tunnel surrounding rock mass is deduced with the analytical method. The formula consists of time factor to calculate the time needed to reach the certain value of lining resistant pressure,displacement and surrounding rock mass displacement. In view of the tunnel vault sink,the peripheral convergence,the pressure of surrounding rock and the internal force,the reasonable support time for second lining is monitored and analyzed to determine the specific coefficient of surrounding rock deformation formula,and ultimately determine the reasonable support time for tunnel lining. The results are compared with that from site monitoring and the support times of the two are much the same,which validates the correctness of the proposed calculation method.