Morison方程中动水阻力项对桥梁桩柱地震反应的影响

The effect of hydrodynamic drag force in Morison equation on the seismic response of piles

在深水桥梁地震反应分析中,当采用Morison方程来考虑桩等水中横向小尺寸结构上水的作用时,等效为增加了一个附加惯性力项和一个附加阻力项,其中,附加阻力项是非线性的。由于非线性附加阻力项的存在,给采用反应谱方法求解桥梁的地震反应带来不便。本文讨论了非线性阻力项对一般桥梁桩柱结构地震反应的贡献,得到的结论是阻力项的贡献很小,可以忽略。这样,水中桥梁地震反应的计算就得到了很大的简化。

In the analysis of the seismic response of deep-water bridges, Morison equation was always adapted to the lateral small structures. The added drag force of the equation was nonlinear, which made it hard to use response spectrum method. The effect of hydrodynamic drag force on the seismic response of piles was discussed in this paper. Results of analysis illustrated that there was little effect induced by hydrodynamic drag force and the analysis of the seismic response can be simplified correspondingly.