A Study on the Stability of Surrounding Rocks in Construction of Undercrossing Tunnels with Super-large Section Based on Radial Displacement Release Rate of Surrounding Rocks
(1. Department of Surveying and Testing, Shaanxi Railway Institute, Weinan, Shaanxi 714000; 2. Key Laboratory of Transportation Tunnel Engineering, Ministry of Education, Southwest Jiaotong University, Chengdu 610031)
Abstract：
Based on the Liuyuan Tunnel Project on Huanggang-Huangmei High-speed Railway, numerical simula? tion and field measurement methods are adopted to analyze the stability law of surrounding rocks in construction of undercrossing tunnels by full-face construction method and micro-bench construction method, in which the radial displacement release ratio of surrounding rock is used as an indicator for comparison. The results show that the construction of the new tunnel crossing under the air-raid shelter section by micro-bench construction method has outstanding advantages over the full-face construction method in controlling the radial displacement release rate, plastic zone distribution and stability safety factor of the surrounding rocks. The radial displacement release rate and stability safety factor of the surrounding rocks are 46.13% and 2.13 respectively under the micro-bench construction method, and 78.08% and 1.99 respectively under the full-face construction method. The stability of surrounding rocks in construction of undercrossing tunnels is relatively good when the bench length is 3 m. The monitoring data shows that, under the micro-bench construction method, the deformation in the tunnel meets the specified requirements and the deformation values are in good agreement with the simulation results, which further verifies the reliability of the simulation results.
YAN Bo1 ZHANG Junru2 ZHANG Xinjin1 PENG Lei1 Ning Bo1
.A Study on the Stability of Surrounding Rocks in Construction of Undercrossing Tunnels with Super-large Section Based on Radial Displacement Release Rate of Surrounding Rocks[J] MODERN TUNNELLING TECHNOLOGY, 2023,V60(2): 115-124
2023, Vol. 60 