近场地震作用下深水桥墩的地震响应分析

近场地震以具有较大的PGV／PGA值及明显的速度脉冲为主要特征，本文分析了不同类型的近场地震对深水桥墩地震响应的影响；采用Morison方程的基本理论，将水视为附加质量，利用有限元方法来分析动水压力对深水桥墩地震响应的影响。通过计算分析得出：具有较大PGV／PGA值的近场地震波会引起桥墩结构较大的地震响应；动水压力对桥墩结构的地震响应有显著的影响，同时近场地震的速度脉冲效应会进一步增大动水压力对深水桥墩地震响应的影响；在矩形深水桥墩设计中，要考虑截面形状效应的影响，选择合适的D／B值。

Seismic Response Analysis of Bridge Pier in Deep Water Excited by Near-fault Earthquakes

A near-fault earthquake usually has the features of larger value of parameter PGV/PGA and obvious velocity pulse. The effect of near-fault earthquakes of the different types on seismic responses of bridge pier in deep water is studied in this paper. With the famous Morison Equation, the water is considered as the added pseudo mass, and the finite method is used to analyze the seismic responses of bridge pier. An actual bridge pier is analyzed, and the results show that, the near-fault earthquake that has the larger value of parameter PGV/PGA will cause the stronger seismic response; the effect of hydrodynamic pressure to seismic responses of bridge pier is notable, and the velocity pulse of near-fault earthquake will make the effect on seismic responses larger caused by hydrodynamic pressure; when designing the rectangular pier in deep water, the section shape effect should be considered and the appropriate value of parameter D/B should be secected.