Deformation characteristics and safety assessment of a high-speed railway induced by undercutting metro tunnel excavation

• Published in: Journal of Rock Mechanics and Geotechnical Engineering Vol. 11; no. 1; pp. 88 - 98
• Main Authors: Qian, Wangping, Qi, Taiyue, Zhao, Yunjian, Le, Yizhou, Yi, Haiyang
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.02.2019; School of Civil Engineering, Southwest Jiaotong University, Chengdu, 610031, China%China Railway Design Corporation, Tianjin, 300142, China%China Changjiang Construction Investment Corp. Ltd., Chengdu, 610000, China%North China Institute of Science and Technology, Langfang, 065201, China; Key Laboratory of Transportation Tunnel Engineering, Ministry of Education, Southwest Jiaotong University, Chengdu, 610031, China; Elsevier
• Subjects: Case application; High-speed railway; Metro tunnel excavation; Numerical simulation; Safety assessment; Settlement characteristics; Numerical simulation; Metro tunnel excavation; High-speed railway; Settlement characteristics; Safety assessment; Case application
• ISSN: 1674-7755
• DOI: 10.1016/j.jrmge.2018.04.014

Stratum deformation (settlement) is a challenging issue in tunnel engineering, especially when construction of metro tunnels has to undercut high-speed railway. For this purpose, we used the FLAC3D software to analyze the stratum settlement characteristics of high-speed railway at different crossing angles intersected by metro tunnel, in terms of ground settlement trough, stratum slip line and irregularity of ballastless tracks. According to the evolution of the stratum settlement at different angle regions, an optimized angle is proposed for the actual project design. In order to reduce the influence of stratum settlement on the safety of high-speed railway, an approach of safety assessment is proposed for the shield engineering undercutting high-speed railway, as per Chinese specifications using numerical results and on-site conditions. A case study is conducted for the shield tunnel section crossing the Wuhan – Guangzhou High-speed Railway between the Guangzhou North Railway Station and the Huacheng Road Station, which represents the first metro tunnel project passing below a high-speed railway in China. A series of measures is taken to ensure the safe excavation of the shield tunnel and the operation of the high-speed railway. The results can provide a technical support for performing a safety evaluation between high-speed railways and metro tunnels.