Bending tests of segment joint with complex interface for shield tunnel under high axial pressure
Feng Kun1,2 He Chuan1,2 Xiao Mingqing3
1. Key Laboratory of Transportation Tunnel Engineering of the Ministry of Education, Southwest Jiaotong University, Chengdu 610031, China;
2. School of Civil Engineering, Southwest Jiaotong University, Chengdu 610031, China;
3. China Railway Siyuan Survey and Design Group Co., Ltd., Wuhan 430063, China
Abstract：When using shield tunneling method facing the special circumstances such as large depth, high water pressure, the complex interface joints with tenon or mortise, and bilateral sealing were widely used. And in which case the bending performance of segmental joint is more complex. With the Shiziyang tunnel project of Guangzhou-Shenzhen-Hong Kong high-speed railway taken as an example, the full-scale tests were carried out to study the bending behavior and failure characteristics of segment joint with complex interface under high axial pressure. The results show that the bending stiffness of the segment joint with complex interface under high pressure linearly increases under small bending moment in the initial stage, but the behavior appears to be obviously nonlinear in the later stage. Moreover, the higher the axial force level is, the longer the linear stage shall be. Due to the participation of concrete in the inner-side contact force-transferring region at hogging bending into compression, the bending resistance of the interface can be increased, leading to a slightly larger bending stiffness at hogging bending compared to that at positive bending. The joint opening condition may change with bending moment in the step-like style. When the interface linearly opens, the increase of axial force appears to have an unobvious restraint on the opening of interface, but in the nonlinear stage, an obvious restraint from the axial force on the magnitude of interface opening can be observed. Influence of sealing material on bending stiffness of joint is small, so that it can be ignored in the design and analysis of bending stiffness of segment joint. The failure processes of segment joint under the positive bending load and negative bending load are different. Under the positive bending load the joint bolt may fail before the damage of joint, while under the negative bending load the joint bolt may not fail although the joint already fail. The research can provide an important reference for shield tunnel design, construction and related research.
封坤 何川 肖明清 . 高轴压作用下盾构隧道复杂接缝面管片接头抗弯试验[J]. 土木工程学报, 2016, 49(8): 99-110.
Feng Kun He Chuan Xiao Mingqing. Bending tests of segment joint with complex interface for shield tunnel under high axial pressure. 土木工程学报, 2016, 49(8): 99-110.
