二次衬砌技术在水利工程隧洞中的应用研究

Research on the Application of Secondary Lining Technology in Hydraulic Engineering Tunnels

二次衬砌是隧洞开挖支护的关键结构。文中结合实例建立“隧洞+二次衬砌”耦合模型,并对不同开挖方式以及不同支护工况下二次衬砌变形进行分析对比。结果表明,全断面光面爆破法开挖时二衬的变形小于三台阶法开挖时二衬的变形,且位移分布较均匀。在满足工程安全的情况下,增加二衬强度并不能大幅度降低二衬位移,在考虑经济性条件下,二次衬砌无需保守设计。

Secondary lining is a key structure for tunnel excavation support.This article establishes a coupling model of"tunnel+secondary lining"with examples,and analyzes and compares the deformation of secondary liningu nder different excavation methods and support conditions.The results show that the deformation of the second lining during full face smooth blasting excavation is smallert han that of the third step excavation method,and the displacement distribution is relatively uniform.Increasing the strength of the secondary lining while meeting engineering safety requirements does not significantly reduce the displacement of the secondary lining.Consideirng economic conditions,conservative design is not necessary for the secondary lining.