径向非均质粘弹性单相土中管桩纵向振动特性分析

发布时间：2018-04-03 12:47

本文选题：管桩-土耦合纵向振动　切入点：径向非均质土　出处：《大连海事大学》2017年硕士论文

【摘要】：本文研究了在径向、双向非均质土中,管桩桩顶受纵向激振力的动力响应问题。首先,根据桩周围土体、管桩的本构关系,建立非均质土的平面波动方程及一维粘弹性管桩的波动方程,由管桩-土接触面的连续及相应的边界条件,得到方程解的待定系数,求得管桩桩顶的阻抗函数的解析解,在此基础上,系统深入的研究了弹性桩与非均质土在纵向振动力作用下的动力耦合振动问题。主要工作如下:(1)基于波动方程的基本理论,根据定解问题确定管桩的一维波动方程及土体平面应变的波动方程。在此基础上研究实心桩、管桩在粘弹性单相土中的纵向振动问题,用Mathematic编程,然后根据参数的变化,得到桩顶复刚度曲线,最后根据已有实心桩文献对比分析,得到管桩的一些相关结论。(2)考虑到地基土在施工过程中受到动荷载扰动,使得桩周土和桩芯土性质沿径向呈非均质性,将土体沿径向分为内、外部区域,内部扰动区域划分为多圈层,各圈层之间连续接触,建立径向非均质土体的平面应变模型,根据土体动力方程和阻抗函数的传递性,用解析法求得桩周土、管桩接触面上的剪切复刚度,即得到桩周土对管桩的作用表达式,用Mathematic编程,得到桩顶复刚度和速度导纳曲线,基于土体参数的变化,对径向非均质土体管桩-土纵向耦合振动进行研究。(3)同时考虑桩周土纵向、径向非均质性,建立在径向非均质土平面应变模型基础上考虑纵向成层土中的管桩纵向振动问题,求得管桩桩顶动力阻抗函数解析解。通过对土体参数研究,对双向非均质土中管桩桩顶动力响应特性进行研究。
[Abstract]:In this paper, the dynamic response of pipe pile top subjected to longitudinal excitation in radial and bidirectional heterogeneous soil is studied.Firstly, according to the constitutive relation of soil around pile and pipe pile, the plane wave equation of heterogeneous soil and the wave equation of one-dimensional viscoelastic pipe pile are established. The undetermined coefficient of the equation solution is obtained from the continuity of the interface between pipe pile and soil and the corresponding boundary conditions.The analytical solution of impedance function on the top of pipe pile is obtained. On this basis, the dynamic coupling vibration of elastic pile and heterogeneous soil under the action of longitudinal vibration force is studied systematically and deeply.The main work is as follows: (1) based on the basic theory of wave equation, the one-dimensional wave equation of pipe pile and the wave equation of soil plane strain are determined according to the definite solution problem.On this basis, the longitudinal vibration of solid pile and pipe pile in viscoelastic single-phase soil is studied. Mathematic is used to program, and then according to the change of parameters, the complex stiffness curve of pile top is obtained. Finally, according to the literature of solid pile, a comparative analysis is made.Some relevant conclusions of pipe pile are obtained. (2) considering that the foundation soil is disturbed by dynamic load during construction, the properties of soil around pile and pile core soil are heterogeneity along radial direction, and the soil is divided into inner and outer region along radial direction.The region of internal disturbance is divided into multiple circles, and the contact between each layer is continuous. The plane strain model of radial heterogeneous soil is established. According to the dynamic equation of soil and the transitivity of impedance function, the soil around pile is obtained by analytical method.The shearing complex stiffness on the contact surface of pipe pile is obtained, that is, the action expression of soil around the pile on the pipe pile is obtained, and the complex stiffness and velocity admittance curve of the pile top are obtained by Mathematic programming, based on the change of soil parameters.The longitudinal vibration of pipe pile and soil in radial heterogeneous soil is studied. (3) considering the longitudinal and radial heterogeneity of soil around the pile, the longitudinal vibration of pipe pile in longitudinal layered soil is considered on the basis of plane strain model of radial heterogeneous soil.The analytical solution of the dynamic impedance function on the top of pipe pile is obtained.Through the study of soil parameters, the dynamic response characteristics of pipe pile top in bidirectional heterogeneous soil are studied.
【学位授予单位】：大连海事大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU473.1

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