Numerical study of mechanical response of shield tunnel under vehicle collision

Abstract

Shield tunnels account for an essential part of the urban highway system, which are more likely to encounter terrible traffic accidents during daily operation. There is a risk of collision between the errant vehicle and the shield tunnel when a traffic accident occurs. This paper establishes a refined numerical model of the shield tunnel based on the Wuhan Yangtze River Tunnel and the vehicle numerical model. Considering the four factors (vehicle weight, speed, collision angle, ground reaction coefficient), an orthogonal test scheme designing 9 simulation cases is proposed. During the collision, the dynamic responses (opening and dislocation of segment joints, stress, and plastic damage of shield tunnel lining) are studied. Results show that the anti-collision wall and segment lining are damaged to varying degrees, and bolts and reinforcement bars in the collision area reach their yield strength; meanwhile, segment joints appear to have irreversible opening and dislocation. According to the extremum difference analysis of orthogonal simulation results, vehicle weight and speed are the two leading factors in structural responses, the contribution degree of which is significantly larger than collision angle and ground reaction coefficient in structural responses.