考虑桩-土相互作用的深水桥墩地震响应分析  

SEISMIC ANALYSIS OF BRIDGE PIER IN DEEP WATER CONSIDERING PILE-SOIL INTERACTION

作　　者：陈宇 吴佳梁 吴堃 黄信 李长辉 CHEN Yu;WU Jia-liang;WU Kun;HUANG Xin;LI Chang-hui(School of Transportation Science and Engineering,Civil Aviation University of China,Tianjin 300300,China)

机构地区：[1]中国民航大学交通科学与工程学院,天津300300

出　　处：《工程力学》2024年第8期176-184,共9页Engineering Mechanics

基　　金：国家自然科学基金项目(51808270);天津市教委科研计划项目(2021KJ059)。

摘　　要：深水桥梁往往为桩基础形式,其地震作用下桩-土相互作用效应显著,掌握桩-土相互作用对深水桥墩地震响应的影响,有助于指导深水桥梁结构的抗震设计。该文通过附加质量方法考虑动水压力作用,采用精细化模型模拟桩-土相互作用,引入动力松弛技术完成初始地应力平衡,建立了考虑桩-土相互作用的深水桥墩地震响应数值模拟方法,并通过离心机振动台试验验证了其正确性。利用已验证的数值模拟方法分析了不同地震强度和不同场地土体强度对深水桥墩地震响应的影响,结果表明:随着场地土体强度提高,桥墩的地震位移响应减小,水体的存在不会改变此规律;软弱土场地的动水压力对桥墩和桩基的地震响应影响较小,最大影响程度在10%左右;中硬土场地的动水压力明显增大桥墩和桩基的地震响应,且地震强度越大,增大效应越明显,因此强震作用下处于硬土场地的动水压力作用在桥梁结构抗震设计中必须予以考虑。The seismic effect of pile-soil interaction on deep-water bridges with pile foundation is significant,and it is important for seismic design of these bridges to consider the effect of pile-soil interaction.A numerical simulation method for seismic response of bridge piers is proposed considering both the hydrodynamic pressure by additional mass method and the pile-soil interaction by a fine model,in which the initial ground stress is introduced by dynamic relaxation method.The proposed simulation method is verified through a centrifuge shaking table test.Then,the influence of seismic intensities and soil strengths on the seismic response of a deep-water bridge pier is analyzed.The results show that the pier displacement decreases as the soil strength increases,and the rule is not affected by the existence of water bodies.The hydrodynamic pressure has a small effect(less than 10%)on the seismic responses of the pier and the pile in soft foundation.The seismic responses of the pier and the pile in hard foundation increase significantly with the hydrodynamic pressure considered,and the amplitude increases with the seismic intensity.Therefore,the effect of hydrodynamic pressure on deep-water bridge structures in hard foundation under strong earthquakes must be taken into consideration in seismic design of bridge structures.

关 键 词：桥梁结构 离心机振动台试验 桩-土相互作用 动水压力 数值分析 地震响应 

分 类 号：U443.22[建筑科学—桥梁与隧道工程] U441.3[交通运输工程—道路与铁道工程]