考虑围岩蠕变特性的TBM隧道管片衬砌受力特性研究

为研究深部高地应力岩层中修建TBM隧道时管片衬砌结构的力学行为,以某深埋TBM工法隧道为研究对象,建立基于围岩蠕变和管片分块效应的衬砌-围岩复合模型,研究考虑时间效应下管片衬砌的受力特性。结果表明:考虑围岩蠕变效应下管片衬砌受力表现出明显的时间效应。随着围岩蠕变时间的延长,管片衬砌的形变、内力和接缝张开量均呈现两阶段增长,具体表现为前期呈线性增长,后期增加趋缓。洞周围岩应力经历三阶段变化,即先减小后增大直至稳定。围岩蠕变时间为100年时,管片衬砌的内力和形变量均接近极限值。研究结果可为深部高地应力且考虑围岩蠕变效应下的TBM隧道衬砌结构设计提供参考。

Study on the Behavior of Segmental Lining of Shield Tunnel under Creep Effect of Surrounding Rock

In order to study the behavior of the segmental liner of TBM tunnel in great depth under high ground stress, this paper takes a deep buried TBM tunnel as the research background to establish a composite model based on surrounding rock creep and segment partitioning effect to study the mechanical property of the segment lining under the creep effect of surrounding rock. The results show that the liner behavior is obviously affected by the creep effect of the surrounding rock. With the increment of both internal force and deformation of segmental lining as well as opening of joint, the deformation and internal force of liner show a two-stage growth, which is demonstrated by a linear growth in the early stage and a slower increment later. The stress of surrounding rock undergoes a three-stage change with a decrement first and then an increase until it is stable. When the creep lasts 100 years, the values of internal force and deformation of the liner are close to the limits. The research results can provide reference for the design of deep tunnel lining structure with high ground stress under the effect of surrounding rock creep.