Experimental and Numerical Study on Damage Characteristics of the Shield Tunnel Segment Under Blast Impact Loading

Abstract

The impact-resistant capacity of the subway tunnel lining is significant to prevent the subway tunnels from the serious damage under the blast impact loading. In this paper, the light gas gun experiment of the shield tunnel segment is carried out. The impact loading generated by light gas gun is used to simulate the blast impact loading. The strain variation characteristics and the damage crater of the shield tunnel segment are analyzed based on the experimental results. Three-dimensional finite element simulations of the specimens under the impacts of bullets with different velocities are also performed using the dynamic finite element program LS-DYNA, and their reliability are verified by the experimental data. Based on the numerical simulation results, the stress states of the elements of the shield tunnel segment are investigated to understand the damage mechanism. The damage levels of the shield tunnel segment under different blast impact loading are also studied. The relationship model between the impact velocities of the bullets and the impact loading is established. The damage depths of the shield tunnel segments under different blast impact loadings are quantified. Finally, the effect of concrete strength on the damage of shield tunnel segment is studied.