考虑地下水、注浆及衬砌影响的深埋隧洞弹塑性解

Elastoplastic solution for deep tunnel considering influences of groundwater,grouting and lining

对于深埋隧洞,地下水-围岩-注浆圈-衬砌共同形成了一个水压平衡体系,传统的隧洞应力与塑性区计算方法均未同时考虑上述4个因素的共同作用。以深埋隧洞为研究对象,将围岩、注浆圈、衬砌视为均质各向同性连续弹塑性介质,基于地下水动力学、弹塑性力学及摩尔-库仑屈服准则,推导了4个因素共同作用下深埋隧洞轴对称问题的应力弹塑性解与塑性区计算公式;利用Matlab编制程序对某隧洞工程进行了计算,并与传统计算方法进行了对比,验证了公式的正确性,指出了传统计算方法的缺陷;讨论了注浆参数对塑性区的影响规律,提出了最优注浆圈厚度的确定方法。

The water pressure equilibrium system of deep tunnel is composed of groundwater,surrounding rock,grouting ring and lining,which can not be systematically investigated by the traditional methods for the stress and plastic zone of tunnel.The elastoplastic solution for deep tunnel is carried out.The surrounding rock,grouting ring and lining are assumed as isotropic continuous elastoplastic medium.Based on the elastoplastic mechanics,groundwater hydraulics theory and Mohr-Coulomb criterion,the calculation formulas for stress and plastic zone of axisymmetric deep tunnel under the combined action of four factors are deduced.To calculate a deep tunnel,Matlab is adopted to edit routine for the computation.Compared with the calculated results obtained from the traditional solutions,the correctness of deduced formulas is validated;and the defects of traditional methods are indicated.The influence of grouting parameters on plastic zone and the method for deciding optimum thickness of grouting ring are also discussed.