基于势流体理论,针对一典型实体矩形截面桥墩,分析了不同水深时,动水对桥墩自振特性的影响.研究了不同水深和地震波类型等条件下,作用于桥墩上动水压力的分布规律及其合力作用点位置,并分析了动水对矩形截面桥墩在地震作用下动力响应的影响.结果表明,由于动水和结构相互作用的影响,矩形截面桥墩的自振周期、墩底弯矩及剪力的峰值会随着水深的增加而不断增大.动水使墩底弯矩和剪力分别最多增大了31%和50%,因此动水对桥墩动力反应的影响不可忽略.并且,不同类型地震波对作用于桥墩上的动水压力分布的影响也不相同.根据日本规范计算作用于矩形截面桥墩上的动水力的结果与本文的结果更为接近.
Based on the potential flow theory, the influence of water on the natural vibration characteristics of a typical rectangular entity pier as the prototype was analyzed at different water depths. As the same time, the distribution of hydrodynamic pressure acting on the pier, the action spot of hydrodynamic force and the effect of water on the seismic response of the pier were analyzed under the condition of different water depths and types of seismic loads. The results show the natural vibration period, the peak values of bending moment and shear force at the bottom of the pier increase with the rise of water depth. The bending moment and shear force increase by 31% and 50% at most respectively, which indicate that the effect of water on the dynamic response of the pier should not be ignored. The influence of different seismic waves on the distribution of hydrodynamic pressure acting on the pier is not identical. The results of hydrodynamic force acting on the pier according to the Japanese specification are closer to data in this paper.