Experimental investigation of mechanical characteristics of bolted endplate joint and construction technology system of prefabricated spatial reticulated grid arch in underground support
Song Yuan1,2 Huang Mingli1,2 Zhang Xudong3 Sun Tong1,2
1. Key Laboratory for Urban Underground Engineering of the Education Ministry, Beijing Jiaotong University, Beijing 100044, China；
2. School of Civil Engineering, Beijing Jiaotong University, Beijing 100044, China；
3. China Railway 11th Bureau Group Co., Ltd., Wuhan 430061, China
Abstract：To solve the problems of slow progress, low mechanization, and high risk in the construction of shallow buried large cross-section tunnels in complex urban environments, this study designed a prefabricated spatial reticulated grid (SRG) support structure with high strength and large stiffness, based on the concept of “timely support, strong support”. To investigate the deformation characteristics and mechanical properties of the primary support in the tunnel and optimize the structural parameters, this study considered the influence of the steel tube diameter and wall thickness, and investigated the bearing capacity of the bolted endplate joint components of the SRG. The failure mode, ultimate bearing capacity, bending deflection, and stress-strain evolution law was analyzed. The load-deflection curves show that the SRG structure went through the elastic growth, plastic development, and ultimate failure stages. The ultimate bearing capacity and flexural stiffness of the structure improved to varying degrees by increasing the steel tube diameter and wall thickness, and the stress-strain state also improved. The thickness of the steel tube wall had a more significant impact on the mechanical properties of the innovative support structure. In the field test, the overall force of the arch frame exhibitedthe characteristics of “larger on the upside and smaller on the downside” and “uneven symmetry”. The stress on the arch shoulder and vault was generally larger, followed by the arch waist and the arch foot was the smallest. Mechanized installation can significantly improve the efficiency of arch erection and the level of mechanized operation, and ensure the safety and reliability of the construction. The results not only reveal the support types of underground structures, but also provide an important theoretical basis for the structural design, parameter optimization, and widespread application of this structures in related projects.
宋远 黄明利 张旭东 孙桐. 隧道装配式空间网架螺栓端板节点力学特性及施工技术体系研究[J]. 土木工程学报, 2021, 54(S): 131-139.
Song Yuan Huang Mingli Zhang Xudong Sun Tong. Experimental investigation of mechanical characteristics of bolted endplate joint and construction technology system of prefabricated spatial reticulated grid arch in underground support. 土木工程学报, 2021, 54(S): 131-139.
