盾构隧道凹凸榫-斜螺栓形式环缝径向顺剪抗剪刚度研究

Radial Shear Stiffness of Circumferential Joint Along Shear Direction with Concave-Convex Tenon and Diagonal Bolt in Shield Tunnel

为研究盾构隧道环缝径向顺剪的抗剪性能,针对凹凸榫-斜螺栓形式的环缝,建立环缝径向顺剪抗剪刚度模型;将环缝的径向顺剪过程分解为静摩擦作用、螺栓锚固、螺栓弯曲变形以及凹凸榫咬合4个阶段,分析不同阶段环缝的受力特点及抗剪刚度的主要构成,并通过解析方法得到4个阶段抗剪刚度的显式解答。选取足尺环缝径向剪切试验的试验结果对螺栓作用阶段抗剪刚度理论模型进行验证并分析误差来源,结果表明,由于螺栓的装配方式、环缝剪切试验中结构的受力变形原理等因素,理论模型与试验结果存在差异,但变形阶段存在一定的相似性,理论模型能够较正确地描述环缝剪切过程中螺栓的力学行为。选取带榫管片环缝剪切试验对分布式凹凸榫在咬合阶段的抗剪刚度进行验证,结果表明,当纵向力较大时(达到2000 kN),凹凸榫抗剪刚度的试验结果与理论模型计算结果接近,说明该模型能够较准确地描述在纵向力较大的情况下环缝剪切过程中凹凸榫的力学行为。

To investigate the radial shear along the shear direction of the circumferential joint in shield tunnels,a radial shear stiffness calculation model based on concave-convex tenons and diagonal bolts is established.The development of radial shear along the shear direction in the circumferential joint is analyzed in four stages:static friction,bolt anchoring,bolt bending,and concave-convex tenon occlusion.The mechanical characteristics and main components of shear stiffness of the circumferential joint in each stage are analyzed using an analytical method.By comparing experimental data with theoretical model results,it is found that:The differences in bolt assembly methods and deformation mechanisms of the structure lead to differences between the theoretical model and test results;During the deformation stage,the results are similar,indicating that the calculation model is capable of accurately describing the shear characteristics of the circumferential joint in the shear process.The experimental data of the loading test of the tenoned segment is compared with the theoretical model.The results indicate that when the longitudinal force reaches 2000 kN,the experimental results of the shear stiffness of concave-convex tenon are close to the theoretical model calculation results,which indicates that the theoretical model can accurately describe the mechanical behavior of tenons in the process of shearing under the condition of large longitudinal force.