Analysis and Considerations of an Express Railway Tunnel Lining Failure by Seasonal Karst Conduct Flow
(1 School of Civil Engineering of Southwest Jiaotong University, Key Laboratory of Transportation Tunnel Engineering, Ministry of Education, Chengdu 60031; 2 Chengdu Railway Bureau, Chengdu 610082; 3 School of Civil Engineering, Central South University,Changsha 410075; 4 China Railway Southwest Research Institute Co. Ltd., Chengdu 611731)
Abstract：
It is very common for railway tunnel linings to have some undiscovered quality defects due to various un?
favorable factors in the construction process, which may threaten operational safety and transportation order; can cause accidents; and may result in property loss and shut down train operations. In this paper, using a crushing failure at a thin sidewall lining due to seasonal karst conduct flow as an example, we analyze water pressures that the tunnel lining bears related to the design lining thickness and insufficient sidewall lining thickness. Results show that the tunnel lining cannot bear the peak pressure that might be produced by a seasonal karst conduct flow although the lining design meets relative requirements; however, water pressure is reduced because the local sidewall is crushed due to insufficient thickness, possibly avoiding the risk of a larger and entire failure of the lining structure. Regarding a tunnel with seasonal karst conduct flow, it is necessary to take corresponding measures to fully mitigate or eliminate risks caused by seasonal high water pressure. Furthermore, the paper reviews problems concerning design alternatives for this project.
2016, Vol. 53 