Loading Characteristics and Damage Effect of Near-Surface Underwater Explosion in Harbor Basin

In order to study the load of underwater explosion near the surface of the harbor basin and the damage effect on the wharf, we designed a typical wharf structure and built a harbor basin environment. Then through a series of numerical analysis which was accomplished based on finite element program LS-DYNA, the explosion phenomenon, loading characteristics, structural dynamic response and energy absorption characteristics were studied in details, the influence rules and action mechanism of the boundary, scaled collapse distance and other parameters were analyzed. The results show that: the explosion bubble pulsation is mainly affected by wharf structure boundary and free surface, the bottom and the movement of fluid in the limited space also have some impacts. The shock wave load is symmetrically distributed in the vertical direction with the scaled explosion depth as the center, and the bubble pulsation load is mainly distributed below the scaled explosion depth. The structural deformation and damage are mainly formed on the propagation of shock wave, and the secondary damage effect of bubble pulsation and jet is weak. Concrete and caisson fill absorb most of the explosive energy.