水下爆炸冲击作用下悬浮隧道响应参数分析

Abstract

To investigate the dynamic responses of submerged floating tunnels (SFTs) subjected to near-field non-contact explosions, the SFT was simplified as a constant-section-and-stiffness Bernoulli-Euler elastic-support beam to establish the SFT dynamic model under underwater shock load. The differential equation for the vibration was resolved with the Galerkin method. The displacement, velocity and acceleration were analyzed for the SFT, the influences of the explosive quantity, the blasting distance and the vertical stiffness of anchor cables were discussed, and the results were also used to analyze the damage of tunnels and human bodies. The results show that, the impact of the blasting distance on the kinematic parameters of the SFT is significant. Moreover, the maximum displacement of the tunnel decreases in inverse proportion to the blasting distance. Compared with those of the blasting distance of 10 m, the displacements of the tunnel body of 20m and 30 m decrease by 50.7% and 66.6%, respectively. The impact of the explosive quantity on the kinematic parameters of the SFT is significant. Also, the maximum displacement of the tunnel decreases approximately in a low-order power function with the explosive quantity. Compared with those of the explosive of 20 kg, the displacements of the tunnel body of 40 kg and 60 kg increase by 29.8% and 51.3%, respectively. The impact of the vertical stiffness of anchor cables on the kinematic parameters of the SFT is significant. Besides, the maximum displacement of the tunnel decreases approximately in a step-like form with the vertical stiffness of anchor cables. Compared with those of the vertical anchor stiffness of 5×105 N/m, the maximum displacement of the tunnel body of 5×10⁶ N/m and 5×10⁷ N/m decrease by 53.0% and 86.2%, respectively. However, there is an efficiently acting interval for the anchor cable stiffness. The stiffness has significant influence on the displacement of the tunnel body within the interval, but has little influence outside the interval (large or small).