宏基大桥深水高墩大跨连续刚构桥地震响应分析

已有研究表明，深水高桥墩在地震作用下，由于桥墩与水的相对运动，水会对桥墩水下部分产生动水压力．以深水库区主跨为220m，墩高为173m的宏基大桥为例，利用Morison方程所得的圆形墩附加质量公式的矩形修正公式模拟水对桥墩的作用，建立了该桥考虑附加质量影响的变截面三维有限元模型，进行该桥的反应谱和时程反应分析．结果表明由于动水压力的作用，不仅使桥梁结构的自振频率明显降低，而且使梁体和桥墩的位移和内力显著增大．本文研究方法与所得结论可为同类桥梁的抗震设计提供参考．

Seismic Response Analysis of a Large-span Continuous Rigid Frame of Hongji Bridge with High Piers in Deep Water

As a result of the bridge pier and the water relative movement, the hydrodynamic pressure acts on the piers. In this paper,a continuous rigid frame bridge is taken as an example which has the main span of 220 meters and pier high of 173 meters. Using the Morison equation, the variable cross-section three dimensional finite element model of this bridge is set up. The bridge is carried on response spectrum and time-history response analysis. The results show that under the action of the hydrodynamic pressure, the natural vibration frequency of the bridge decreases obviously and the displacement and internal force of pier and beam increases remarkably. The research methods and conclusions are useful to the design of similar bridges.