预制装配式地铁车站结构榫槽式接头力学性能研究

Mechanical Property of Tenon-Groove Joints for Metro Station Constructed by Prefabricated Structure

以明挖地铁车站预制装配结构的榫槽式接头为研究对象,通过有限元数值模拟方法研究接头构件的应力演变规律及其接缝变形和接缝张开角与加载弯矩的关系,并与接头构件的足尺加载试验结果进行对比分析。数值计算和加载试验的结果均表明:在设计最不利轴力为1 600kN的工况下,随着加载弯矩的增大,榫槽接缝部位的应力变化明显,而榫头端部的应力基本保持稳定,因此预制装配地铁车站结构采用榫槽式接头能够有效提高接头抵抗弯矩的能力;当加载弯矩小于300kN·m时,榫槽接缝部位的变形量很小,而当加载弯矩超过400kN·m以后,榫槽接缝部位的变形量发生突变,因此从结构的抗裂要求和榫槽式接头的整体力学性能考虑,维持榫槽式接头正常工作状态的弯矩值大约在350kN·m左右。

The tenon-groove joint of the prefabricated structure for open-cut metro station was taken as the research object. The stress evolution law of the joint component, the relationships between the joint deformation and joint opening angle with the loading moment were studied by finite element numerical simulation method. The calculation results were compared with those obtained from the full-scale loading test of joint component. The results of both the numerical simulation and loading tests indicated that, under the most unfavorable working condition of the design axle force of 1 600 kN, the stress of tenon-groove joint parts changed obviously with the increase of loading moment while the stress of tenon end almost re- mained no change. Accordingly, the tenon-groove for metro station constructed by prefabricated structure could effectively improve the ability of the joint to resist bending moment. The deformation of tenon- groove joint was very small as the loading moment was less than 300 kN ·m and the joint deformation changed abruptly as the loading moment was more than 400 kN·m Therefore, considering the crack resistance requirement of the structure and the mechanical properties of the tenon-groove joint as a whole, the bending moment value for maintaining the tenon-groove joint under normal working state was about 350 kN ·m.