地震作用下桥梁下部结构和水体的动力相互作用问题通常采用有限元法结合动水压力公式的混合方法进行求解。对于高承台群桩基础桥墩,已有研究者建议了一种动水压力的附加质量模型,即桥墩和水中承台的动水压力分别采用圆柱和圆盘结构的辐射波浪解析解、水中桩的动水压力采用Morison方程。此时动水压力附加质量模型不满足解析条件,该方法是近似的,但目前尚未见到验证该方法适用性的研究工作。本文将流-固耦合实体有限元模型作为参考标准,通过与其进行对比,研究高承台群桩基础桥墩动水压力附加质量模型的适用性。研究结果表明:两种模型的计算结果存在一定差异,但附加质量模型的计算结果基本能够满足精度要求。
The finite element method and hydrodynamic pressure formula is adopted to calculate the dynamic interaction between bridge substructure and water under earthquake action. The researchers have proposed a hydrodynamic added mass model for the bridge pier on high cap pile group foundation,and this model is based on the analytical solution of the hydrodynamic pressure on the pier and cap and the Morison equation for the pile group foundation. This method,which is approximate to the hydrodynamic added mass model,does not satisfy the analytical conditions,and there is a certain lack of effective study on the applicability of this method now. Compared with the fluid-solid coupling finite element model,this paper studies the applicability of the hydrodynamic added mass model. The results indicate that the hydrodynamic added mass model can meet the precision requirement although the solutions of the two models exist certain differences.