舶舶撞击荷载作用下桥梁桩基复合体系动力损伤特性分析

Analysis of dynamic damage characteristics of bridge and pile foundation under the impact of shiploads

基于混凝土塑性动力损伤理论,利用ABAQUS三维非线性动力有限元法,对船舶撞击荷载作用下,桥梁桩基复合承载体系动力响应及损伤特性进行分析研究。研究表明:船桥撞击力随撞击速度增大呈线性增长,撞击角度对撞击力显著影响,撞击角度越大,撞击力峰值显著降低。桩身位移与弯矩值均随船舶撞击速度的增大而增大,桩身最大位移和最大弯矩值并非发生在撞击点处,而是在撞击点以下某一位置,具体位置取决于桩顶与桥面结构之间的约束程度。船桥碰撞荷载作用下桥梁桩基复合体系的动力损伤以拉伸损伤为主,压缩损伤区域相对较少。桥梁结构设计时应重点加强桩基与桥面结构的联结刚度,适当提高桩基配筋率,以提高桥梁桩基复合体系抗撞击能力。

Based on the plastic dynamic damage theory of concrete,using ABAQUS three-dimensional nonlinear dynamic finite element method,this paper analyzes the dynamic response and damage characteristics of composite system of bridge and pile foundation under the impact of shiploads.The results show that the impact force increases linearly with the increase of impact velocity,and the impact angle has a significant effect on the impact force.The larger the impact angle is,the lower the peak impact force is.The maximum displacement and bending moment of the pile increase with the increase of the ship impact speed.The maximum displacement and bending moment of the pile do not occur at the impact point,but at a certain position below the impact point.The specific position depends on the degree of constraint between the pile top and the bridge deck structure.The dynamic damage of bridge pile foundation composite system under ship bridge collision load is mainly tensile damage,and the compression damage area is relatively small.The bridge structure design should focus on strengthening the connection stiffness of pile foundation and bridge deck structure,and properly improve the reinforcement ratio of pile foundation,so as to improve the anti-collision ability of bridge pile foundation composite system.