Research on Rock Support Technology of Railway Tunnels Based on Geomechanical Model Tests

作者：Zhibiao Guo, Jingwei Gao, Dongshan Yang, Xiaohui Kuai, Yuanxin Zhao, Shenghui Chu · 发表于：International Journal of Geomechanics · 年份：2024 · DOI：10.1061/ijgnai.gmeng-9359 · 被引用次数：2 · 研究领域：Geotechnical and Geomechanical Engineering、Rock Mechanics and Modeling、Geomechanics and Mining Engineering

The technology of combining a negative Poisson's ratio (NPR) anchor cable with a double-layer truss support technology (N-DTST) is a new support technology for deeply buried tunnels. To evaluate the stability of the surrounding rock support after the application of this new support technology in the Sichuan–Tibet Railway tunnels, geomechanical model tests were conducted for the first time. A model test loading system with intelligent numerical control and automated analysis was developed to reveal the changing patterns of displacement and stress in the surrounding rock of tunnels. The test results revealed the following: (1) After the burial depth exceeds 800 m, the tunnel undergoes large deformations with displacements greater than 37.5 mm, and the traditional anchor cable support fails; (2) In the burial depth range of 800–2,000 m, the new support technology can control the surrounding rock deformation, and the surrounding rock displacement is less than 10 mm; (3) After the tunnel excavation, the radial stress decreases and the tangential stress concentrates. When the burial depth is greater than 800 m, the radial stress compensation provided by the anchor cable no longer meets the stability of the tunnel surrounding rock, and the new support technology can provide high stress to support the deeply buried tunnel; (4) After the burial depth exceeds 2,000 m, butterfly-shaped damage occurs on the tunnel surface, the truss structure inside the tunnel is damaged, and the support...