Abstract：Long gas transmission shield tunnels often run through complex strata. Joint, as vulnerable location of segmental lining,is complex in its detail and configuration, and its deformation may easily exceed the design requirements under large bending-compression load causing the damage of segmental linings. In order to investigate the mechanical properties and failure mechanism of the joint under large bending-compression load, a series of prototype tests of the curve-shaped joint were carried out. A detailed description was given to highlight the complete mechanical behaviors, such as stress, deformation and failure, of the segmental disturbed region affected by the joint. Then the relationships between the damage degree and internal force/ deformation of the structure were quantitatively analyzed. The results show that the eccentricity can lead to the extrusion or uplift of the structure, and affect the distribution of segmental bending moment along the circumferential direction. Under large bending-compression load, the failure process can be divided into three stages, namely the slow deformation stage before yielding of bolt, the sudden deformation stage due to yielding of bolt, and the rapid deformation and failure stage after yielding of bolt. When the joint is damaged, the deformation amount is small, and the range of crushed concrete on both sides of the joint is approximately equal to the thickness of the segment. The failure mechanism can be described as follows: the joint open due to the yielding of bolt, resulting in the decrease of the contact area of compressive zone under the elastic sealing gasket the increase of concrete pressure and the collapse of concrete. Subsequently, the concrete at the outer edge of the caulking groove is pressed and finally crushed, leading to the final damage of the joint.
邱月 何聪 何川 封坤 胡熠 郑立宁. 输气盾构隧道原型管片接缝弯压破坏试验[J]. 土木工程学报, 2020, 53(7): 108-115, 128.
Qiu Yue He Cong He Chuan Feng Kun Hu Yi Zheng Lining. Prototype failure tests of segmental joints for gas transmission #br#
shield tunnel under bending-compression load. 土木工程学报, 2020, 53(7): 108-115, 128.
