装配整体式盾构管片结构 及力学性能研究

传统盾构隧道管片由预制管片和螺栓连接而成，需要依靠围岩荷载才能形成稳定的结构体系。接头的存 在也会造成管片结构整体刚度偏低、抗变形能力减弱，影响隧道结构的安全性和耐久性。本文提出一种装配整体 式盾构隧道管片结构，该装配整体式管片由预制 T 型管片和叠合区混凝土组成。盾构施工阶段进行 T 型管片拼装， 隧道洞通后采用喷射或现浇方式进行叠合区混凝土施工。基于 ABAQUS 软件对比分析装配整体式管片和传统管 片的力学性能。结果表明：在施工阶段，装配整体式管片和传统管片的内力相近，但装配整体式管片的变形稍 大。当隧道附近有基坑开挖时，T 型管片与叠合区混凝土共同承担隧道荷载，叠合区混凝土刚度大，对 T 型管片 具有保护作用，并且装配整体式管片的后期变形小于传统管片，表现出更好的整体性和抗变形能力。装配整体式 盾构隧道管片结构适用于非均质或大变形地层，且能更好地应对邻近施工和邻近穿越等工况，可为盾构隧道工程 建设提供新的技术方案。

ructure and Mechanical Properties of Assembled Monolithic Segments in Shield Tunneling

Traditional shield tunnel segments consist of prefabricated segments and bolts, which depend on the surrounding rock load to form a stable structural system. Moreover, segment joints reduce the overall stiffness and deformation resistance of a segmental structure, thereby affecting the safety and durability of the tunnel structure. An assembled monolithic segment was presented in this study. The assembled monolithic segmental structure included prefabricated T-shaped segments and postcast concrete. The T-shaped segments were assembled during shield tunnel boring machine (TBM) tunneling, and the superimposed area of concrete was prepared using shotcrete or cast-in-place after the breakthrough of the tunnel. The mechanical properties of the assembled monolithic and traditional segmental structures were compared using ABAQUS software. The results indicated that the internal force of the assembled monolithic segmental structure was similar to that of the traditional segmental structure during the construction stage; however, the deformation was slightly greater. After the foundation pit was excavated, the T-shaped segments and superimposed area of concrete cooperated to withstand the tunnel load. The superimposed area of concrete provided effective protection to the T-shaped segments owing to its high stiffness. Moreover, further deformationof the assembled monolithic segmental structure was much smaller than that of the traditional segmental structure, which showed better integrity and deformation resistance. The assembled monolithic segment structure is suitable for nonhomogeneous or large-deformation strata and can better handle working conditions such as adjacent construction and adjacent crossing. This technology can provide a new technical solution for TBM shield tunneling projects.