基于水荷载的面力和体力作用理论,建立轴对称计算模型,推导了考虑混凝土开裂特征与围岩开挖松动圈影响的相关计算公式,并编制了对应的计算程序,在此基础上实现了基于通用有限元计算平台的透水衬砌计算仿真分析.计算结果表明:采用体力理论时,钢筋应力和裂缝宽度均明显小于面力理论,围岩承担了绝大部分的水压力,充分体现了围岩是隧洞内水压力承载主体的设计理念,对于隧洞局部围岩条件较差区域仅通过增大钢筋用量不能有效控制隧洞的渗透流量,建议对衬砌外围软弱岩体进行局部置换.
Based on the surface force theory and body force theory of water load,formulas considering cracking property of concrete and excavation disturbed zone of surrounding rock are deduced according to axisymmetric computational models.Then corresponding computer program is compiled.Simulation of permeable lining is also carried out based on the universal finite element program.The results show that when body force theory is adopted,calculated reinforcement stresses and crack width are obviously smaller than surface force theory as the most part of water load is carried by surrounding rock,which fully embodies the design idea that surrounding rock is the key structure of tunnel in load carrying.When condition of partial surrounding rock is poor,raising the reinforcement in concrete lining alone can not effectively reduce the seepage quantity of tunnel.Partial excavation for replacement of surrounding rock would be a better way.