TBM开挖隧洞管片衬砌结构三维有限元分析及配筋计算

Three-dimensional finite element analysis and reinforcement calculation of segment lining structure of TBM excavation tunnel

研究在高内水压力下,TBM开挖隧洞中管片衬砌能否承担内水压力作用且结构强度满足设计要求的问题,主要针对管片衬砌结构接缝对衬砌整体应力的影响。以某水电站长距离引水隧洞为例,采用有限元法建立三维模型,计算发现在内水压力作用下,管片分块衬砌受力规律不同于常规现浇混凝土衬砌,管片之间螺栓连接受力集中,接缝处产生了应力释放,使得管片其他部位应力降低,而且配筋量较同水头下整体现浇混凝土配筋量大大减少。

In this paper, the problems whether the segment lining of TBM excavation tunnel can sustain the internal pressure and structure strength can meet the design requirements under high internal water pressure were investigated, and the effects of segment lining structure joint on the overall stress of lining were analyzed. , Finite element method was used to develop the threedimensional model of a long-distance tunnel at a hydropower station. The results showed that under the internal water pressure, the stress of block segment lining is different from that of conventional cast-concrete lining, stress is concentrated at the bolt connection of segment, stress releases at the seam to cause the decreasing stress in other parts of segment, and the reinforcement concrete volume is greatly reduced compared with that of the overall cast-in-place concrete.