桩顶固定且部分桩体埋入黏弹性地基中时桩的自振特性分析  

Analysis of Vibration Characteristics of Piles with Top Fixed and Part Embedded in a Viscoelastic Foundation

作　　者：柳伟[1] 余云燕[1,2] LIU Wei;YU Yunyan(School of Civil Engineering,Lanzhou Jiaotong University,Lanzhou 730070,China;Gansu Province Engineering Laboratory of Rail Transit Mechanics Application,Lanzhou Jiaotong University,Lanzhou 730070,China)

机构地区：[1]兰州交通大学土木工程学院,兰州730070 [2]兰州交通大学甘肃省轨道交通力学应用工程实验室,兰州730070

出　　处：《噪声与振动控制》2018年第2期127-132,共6页Noise and Vibration Control

基　　金：甘肃省基础研究创新群体资助项目(145RJIA332);兰州交通大学优秀平台支持项目(201606);国家自然科学基金资助项目(51268031)

摘　　要：将回传射线矩阵法推广至桩土系统的振动分析中,采用基于Timoshenko梁理论的Winkler地基模型,运用回传射线矩阵法及求根法求解桩顶固定且部分桩体埋入弹性地基中时桩的自振特性,并与基于有限元分析软件SAP2000的计算结果比较,验证利用回传射线矩阵法求解埋置结构自振特性的有效性和计算精度。同时,分析桩顶固定且部分桩体埋入黏弹性地基中时土体弹簧系数及土体阻尼系数对桩基自振频率和振型的影响。结果表明:随着土体弹簧系数的增大,埋置结构的各阶自振频率增大,土体弹簧系数对衰减系数没有影响,对埋置结构振型的影响较小;随着土体阻尼系数的减小,埋置结构的各阶自振频率增大,衰减系数相应减小,土体阻尼系数对埋置结构的低阶振型影响尤为明显,对高阶振型的影响较小。The reverberation-ray matrix method is extending to the vibration analysis of pile-foundation systems.Based on the Winkler foundation model and Timoshenko beam theory,the vibration characteristics of the pile with top fixed and part embedded in an elastic foundation are solved by the reverberation-ray matrix method and the root method.The calculation result is compared with that of SAP2000 software.The effectiveness and accuracy of this method is verified.Meanwhile,the influences of soil spring coefficient and soil damping coefficient of the foundation on the natural frequencies and modals of the pile foundation are analyzed.The results show that the natural frequency of the embedded structure increases with the soil spring coefficient increasing;the soil spring coefficient has little effect on the attenuation coefficient and has small influence on the modals of the embedded structure;when the soil damping coefficient decreases,the natural frequency of the embedded structure increases and the attenuation coefficient of the embedded structure decreases correspondingly;the soil damping coefficient has an obvious influence on low-order modals and a small influence on highorder modals.

关 键 词：振动与波 回传射线矩阵法 黏弹性 桩基 自振频率 衰减系数 

分 类 号：O321[理学—一般力学与力学基础] O241.82[理学—力学]