侧部岩溶尺度及净距对盾构隧道围岩变形影响分析

以某地铁区间岩溶区盾构隧道修建为工程依托，对隧道三维动态盾构施工过程进行弹塑性数值模拟，分析盾构隧道施工时，溶洞尺寸以及溶洞与隧道间净距对隧道围岩变形及应力等的影响规律。研究结果表明：溶洞对隧道施工过程中围岩变形影响较大，围岩的径向位移及其释放率在有溶洞存在时有增大趋势，同时发现其随溶洞尺寸增加而增大；溶洞尺度及溶洞距盾构隧道间净距对围岩塑性区分布范围及形态以及衬砌结构受力特征等有比较大的影响；通过反复论证，确定了溶洞与盾构隧道问最小施工安全净距不应小于溶洞尺寸。本次研究成果可为岩溶区城市地铁隧道修建提供参考依据。

The Influence of Scale and Spacing Distance of the Lateral Karst Cave on the Surrounding Rock Deformation of a Shield Tunnel TT A %7-

According to the construction of the metro running tunnel in the carst region, with the method of the three - dimensional elastoplastic simulation for dynamic construction process of the shield tunnel, the influence of the cave size and spacing between the ca- ve and the tunnel on the deformation and stress of surrounding rock is analyzed. The study results indicate ： the cave has great influence on the surrounding rock deformation during the shield tunnel construction, the radial displacement of surrounding rock and its release rate show an increase tendency when there exists a cave, and the increase is found with the growth of the cave size ; The cave size and spacing between the cave and the tunnel have great influence on the deformation of surrounding rock, the plastic zone distribution range and distribution form, mechanical characteristics of lining structure. The minimum safety spacing between the cave and the shield tun- nel should not be less than the cave size through repeated demonstration. These results are instructive for the construction of the metro tunnel in carst regions.