One tunnel is being constructed by TBM. Its lining adopts precastconcrete hexagonal segment.
某隧洞工程采用TBM施工，六边形预制钢筋混凝土管片衬砌。
2
In recent years the reinforced concreteprecast element linings are adopted more and more for the soft surrounding rock tunnels. But a perfect assembling method for lining is not performed yet.