Research On Dynamic Response Of Pier Under Ship Crash And Anti-collision Structure

With the rapid development of transportation, ship-bridge collision frequently occurred and has been paid more attention and research. Based on several kinds of mechanical theory and numerical simulation technology, this paper studied the dynamic response and its change law of the pier impacted by ship and discussed the effects of impact parameters on the dynamic response of the pier by using LS-DYNA; summarized the former thought of anti-collision structure design, designed the anti-collision structure, comparatively analyzed the effectiveness of the anti-collision structure and discussed the influence of impact parameters on the dynamic response of the pier and the ship. The main research work and results are as follows:(1)A discrete pier model with add mass and a ship model were built, and a ship-bridge collision process was simulated by using LS-DYNA. By analyzing the dynamic response of the pier and the ship in the collision process, we found the conclusions below: the displacement of the pier column lagged behind the pile cap's; high stress area on the piles appeared in the joint place with cap and the place in the top of soil.(2)The effects of the change of water depth, diameter of piles' longitudinal reinforcement and piles on the dynamic response of the pier and the ship were compared and some conclusions were got below: with the increase of water depth, the displacement of the pier, the shear force and moment of the piles' top sections and the impact depth of the ship increased; as the diameter of the piles' longitudinal reinforcement and the piles increased, the displacement of the pier reduced significantly and the deformation rebound speed of the pier and the impact depth of the ship increased significantly.(3)An anti-collision structure was designed and the dynamic response of the pier and the ship, when the ship impacted the anti-collision structure and direct impacted pier, was compared. By comparatively analyzing, some conclusions were drawn below: the anti-collision structure could have very good cushioning during the crash and could significantly reduce the collision force passed to the pier; the dynamic response of the pier and the ship was reduced after using the anti-collision structure.(4)The effects of the change of water depth, collision place, the intensity of steel round of the anti-collision structure and rubber hardness on the collision result were discussed and some conclusions were drawn below: as the water depth increased, the collision force peak and the dynamic response of the pier increased, the impact depth of the ship was almost the same; when the ship impacted the anti-collision structure cant, the dynamic response of the pier and the ship would reduce a lot; with the increase of the strength of the steel round, the dynamic response of the pier and the ship was increased, and the impact depth of the ship was effected more significantly; when the rubber hardness was too large or too small, the dynamic response of the pier and the ship would be larger, so rubber hardness should be selected reasonably.