Structural Dynamic Response of a Frame Tunnel under Coupled Impact-Explosion Loading

As the main structural bodies of underground facilities such as subway stations, frame tunnel structures play an important role in urban development and construction. In recent years, with the frequent occurrence of explosions after vehicle impacts in tunnels, which have caused severe damage to frame tunnels, the lack of relevant papers makes it necessary to develop a dynamic response analysis of frame tunnels. In this paper, by optimizing the design of an original frame tunnel structure, a dynamic response numerical model of the frame tunnel considering the impact effect of a 3D solidified vehicle and the joint effect is investigated. The deformation trend and damage evolution of the frame tunnel are analysed under different collision masses (1.4, 2.4, 6 and 15 t), collision angles (5, 10, 15 and 75°), collision speeds (60, 80 and 100 km/h), blast delay times (10, 20 and 30 ms) and blast equivalents (50, 100 and 200 kg TNT). This paper improves the active and passive robustness of frame tunnels using both improved operational management and the optimal design of the tunnel structure as a way to ensure the structural safety and functional resilience of frame tunnels.