为得到大直径盾构隧道预制中隔墙底部节点的骨架曲线，并进一步评估预制中隔墙在运营时承受设计荷载的状态，依托广花城际白云城市中心站至方石站（简称白方区间）工程，针对预制中隔墙底部节点的力学性能开展拟静力足尺试验。通过对现浇和预制中隔墙试件进行低周往复加载，得到预制中隔墙底部节点的力学性能。试验结果表明： 1）中隔墙在屈服前主要发生弯曲开裂，裂缝从墙根向顶部逐渐发展。现浇中隔墙由于刚度高，最终发生剪切破坏；而预制中隔墙因未配置环向箍筋，在墙底形成X形斜裂缝并最终导致黏结破坏。2）现浇中隔墙与轨下结构的连接可靠，未发生开裂；而预制中隔墙与轨下结构的连接界面在屈服时出现拉脱现象，但连接界面在试件破坏时仍有较好的承载力。3）现浇和预制中隔墙试件在当前设计荷载下不会开裂，但建议在中隔墙下部设置环向箍筋，增强中隔墙承载力的同时避免墙根下部出现X形斜裂缝。4）现浇中隔墙试件的刚度和承载力均较高，但变形能力和耗能性能较差；而预制中隔墙试件的刚度和承载力略低于现浇中隔墙试件，但延性和耗能性能优异。
The skeleton curve of the bottom joint of prefabricated partition walls in large-diameter shield tunnels is crucial for evaluating the designed load-bearing state of the partition walls during operation. Herein, a case study is conducted at the Baiyun Central station-Fangshi station section of the Guangzhou East railway station-Huadu Tiangui intercity railway, and a quasi-static full-scale experiment is implemented to investigate the mechanical properties of the bottom joints of prefabricated partition walls. Low-cycle loading tests are carried out on cast-in-place and prefabricated partition walls, yielding the mechanical properties of their bottom joints. The main findings are as follows: (1) Partition walls exhibit bending-induced cracking before yielding, with cracks gradually developing from the wall foot to the top. Owing to high stiffness, the cast-in-place wall ultimately undergoes shear failure. In contrast, the prefabricated wall without circumferential stirrups exhibit intersecting diagonal cracks at the wall base, eventually leading to bond failure. (2) The connection between the partition wall and the under-track structure in the cast-in-place specimen is reliable and exhibits no cracking at specimen failure. However, the prefabricated partition wall shows detachment at the connection before yielding, although the connection still maintains adequate load-bearing capacity at specimen failure. (3) The bottom joints of both cast-in-place and prefabricated partition walls do not crack under the current design load. However, it is recommended to install circumferential stirrups at the bottom of the partition wall to enhance load-bearing capacity and prevent the occurrence of X-shaped diagonal cracks. (4) The cast-in-place specimen demonstrates higher stiffness and load-bearing capacity but lower deformation capacity and energy dissipation, whereas the prefabricated specimen, although slightly inferior in stiffness and load-bearing capacity, exhibits superior ductility and energy dissipation performance.
