大断面矩形隧道预制装配式管片接头抗弯性能研究

Study on Bending Properties of Prefabricated Segment Joints in Large Section Rectangular Tunnel

矩形隧道管片接头是连接各管片的重要结构部件,是整个结构受力的关键环节,需要专门对其进行力学性能研究。对此,采用足尺试验的方法对一种特定的管片接头的抗弯性能进行了研究,并将理论计算结果与试验结果进行对比,验证了理论计算方法的准确性。研究结果表明:随着荷载不断增大,管片接头的抗弯性能共有3个阶段,分别是弹性阶段、屈服阶段和强化阶段,每个阶段的抗弯刚度值都明显小于上一阶段;在设计工况下,试件所发生的破坏为大偏心受压破坏,轴向压力对抗弯承载力有一定的贡献,接头的最终破坏是受拉端螺栓破坏所导致的;C形预埋件在受力过程中变形显著,在整个受力过程中对接头提供了较大的塑性变形能力,使得管片接头在受力过程中具有良好的延性。

The segment joint of rectangular tunnel is an important structural member connecting each segment,and it is the weak link of the whole structure,so it is necessary to study its mechanical properties.In this paper,the full-scale experiment is used to study the bending performance of a specific segment joint,and the theoretical calculation results are compared with the experimental results to verify the accuracy of the theoretical calculation.The results show that with the increasing load,the bending stiffness of segment joints has three stages:elastic stage,yield stage and strengthening stage.The bending stiffness value of each stage is significantly lower than that of the previous stage;Under the design condition,the failure pattern of the specimen is large eccentric compression failure.The axial pressure has a few contribution to the bending capacity,and the final failure of the joint is caused by the failure of the bolt at the tensile end;The C-shaped prefabricated component deforms significantly during the stress process,which provides a large plastic deformation capacity for the joint during the whole stress process,making the segment joint have a good ductility during the stress process.