Numerical investigation on the damage and cracking characteristics of the shield tunnel caused by derailed high-speed train

With the extensive application of the shield tunnel, the damage of the shield lining structure due to the impact of the high-speed train draws increasing attention in recent years. In this paper, a nonlinear dynamics analysis model of train-lining-rock is established based on the theory of impact dynamics. Based on the dynamic characteristics and energy conversion characteristics of the high-speed train, the damage evolution and fragmentation characteristics of the shield tunnel are investigated using the plastic damage and brittle cracking constitutive model of respectively. The results show that (1) the interaction between the train and the segment is mainly reflected in the transmission of transverse pressure under the impact; (2) the plastic deformation of the train is the major way to absorb the impact energy; (3) the tensile damage of the shield tunnel is significantly greater than that of the compressive damage; (4) the impact speed has a significant effect on the fragmentation characteristics of the segment lining. Relevant conclusions can provide references for the subsequent design of the anti-impact lining.