中文摘要：

为了研究大断面矩形盾构隧道管片接头结构的力学性能及其极限承载能力和极限破坏状态,进行了该管片接头的极限抗弯承载力试验。试验在同济大学自主研发的盾构隧道管片接头试验加载系统中进行,采用Datataker数据采集系统记录了接头试件在荷载作用下的力学性能变化过程,同时采集并记录了该接头的破坏过程和最终破坏形态。通过分析管片接缝张角、接头处挠度以及双排螺栓应力随接头处弯矩荷载的变化,对该管片接头结构力学性能变化及破坏全过程进行研究,并将其分为3个阶段：弹性变化阶段（弯矩小于450kN·m）、塑性发展阶段（弯矩为450-800kN·m）、屈服破坏阶段（弯矩大于800kN·m）。试验结果表明：正弯矩荷载下该断面形式的大断面矩形盾构隧道管片接头屈服弯矩为800kN·m,极限抗弯承载力为884kN·m,均远大于该管片接头设计荷载（534kN·m）,意味着试验的大断面矩形盾构隧道管片接头可满足抗弯设计的要求,并为类似工程提供参考。管片接头试件的最终破坏形态表明,除了传统圆形盾构隧道管片接头试验中常见的接缝混凝土受压屈服破坏、接头螺栓受拉屈服破坏以外,所研究的大断面矩形盾构隧道纵缝接头出现了新的破坏形态,即接头盒断裂和锚固失效。

英文摘要：

In order to investigate the mechanical behaviors and ultimate bearing capacity and ultimate failure state of the segment joint in a shield tunnel with large rectangular cross-section,the ultimate flexural capacity test of the joint was carried out.The test was conducted in the test loading system for the segment joint of shield tunnel which was developed by Tongji university,and the Datataker data acquisition system was used to record the mechanical property changing processes of the joint specimen under loading.Meanwhile,the failure process of the joint was collected and the final failure form was recorded.By analyzing the changes of the joint rotationalangle,the deflection of the joint and the stress of bolts with the bending moment load,the change of mechanical behaviors of the joint structure and the whole process of damage were explored.It was divided into three stages：elastic stage（bending moment was less than 450kN·m）,plastic development stage（bending moment was in the range of 450-800kN·m）and yield failure stage（bending moment was larger than 800kN·m）.The results show that the yield bending moment of the joint used in this shield tunnel with large-section rectangular is 800kN· m and the ultimate bearing capacity is 884kN·m,much larger than design load（534kN·m）.It means that the tested joint specimen can meet the requirements of flexural design and provides a reference for the similar projects.The final failure pattern of the joint specimen shows that,except the compressive yielding of concrete and tensile yielding of bolts in the conventional test on the segment joint in circular shield tunnels,there is a new failure mode of the segment joint—the crack of joint box and the failure of anchor bars.