High-Speed Railway Tunnel Bottom in Nearly Horizontally Soft and Hard Interlayered Strata: Deformation Mechanism and Countermeasures
Junsheng Yang1, Maolong Xiang1, Jian Wu2, Yuwei Li3, Yipeng Xie1, Jinyang Fu1
1School of Civil Engineering, Central South University, Changsha, China
2China Railway Southwest Research Institute Co., Ltd, Chengdu, China
3Liaoning University, Shenyang, China
Keywords: Railway tunnel, tunnel bottom, gentle incline, interlayered strata, deformation mechanism, countermeasures
Abstract
A large number of cases of tunnel bottom deformation occur in nearly horizontally layered strata. This article analyzes the common characteristics of such tunnel bottom deformation through case studies, and introduces the limitations and requirements for bottom designs for China’s high-speed railway tunnels. The deformation mechanisms of the tunnel bottom were studied through the physical model experiment which revealed the interaction characteristics between the layered surrounding rock and the tunnel bottom structure. Through the numerical simulation study, the effect of different elevated arch curvatures on deformation of the tunnel bottom was investigated, and the effectiveness of elevation arch deepening in deformation control of the tunnel bottom was verified. The classified control countermeasures for deformation at the bottoms of the tunnels in nearly horizontally layered strata are provided.
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