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将地震场地液化土层分为非液化表层土,中部的液化土层以及底部的基层,基于饱和多孔介质理论和No-vak薄层法,研究了液化粘弹性土层中端承桩的动力特性。利用Helmholtz分解得到液化土层对桩水平振动的阻抗。采用Winkler地基模型,利用矩阵传递法,得到桩头复刚度的解析表达式。进行了参数研究,分析了液化土层液化程度、厚度及桩、土物理和几何参数对水平振动端承桩桩头水平、摇摆及水平-摇摆耦合振动动力刚度和阻尼的影响。结果表明:液化土层厚度和液化程度以及桩土模量比等对刚度和阻尼因子有显著的影响,频率对阻尼因子的影响较刚度因子更为显著,但液固耦合系数和土层粘滞阻尼系数对刚度和阻尼因子的影响较小。这些结果有助于揭示液化土中桩基的动力学性能。
Based on the theory of saturated porous media and the No-vak thin-layer method, the dynamic characteristics of end-bearing pile in liquefied viscoelastic soil are studied in this paper. The liquefied soil in the seismic field is divided into non-liquefied topsoil, liquefied soil in the middle part and bottom layer. . The Helmholtz decomposition is used to obtain the impedance of liquefied soil to horizontal vibration of pile. Using Winkler foundation model, the matrix transfer method is used to obtain the analytic expression of complex stiffness of pile head. The influence of liquefaction degree, thickness, physical and geometrical parameters of pile and soil on the dynamic stiffness and damping of horizontal and swaying and horizontal-rocking coupling vibration of horizontal pile end pile are analyzed. The results show that the thickness and liquefaction of liquefied soil, as well as the modulus ratio of pile to soil have a significant impact on the stiffness and damping factor. The influence of frequency on the damping factor is more significant than the stiffness factor, but the liquid-solid coupling coefficient and soil viscous The damping factor has less effect on stiffness and damping factor. These results help to reveal the dynamic behavior of pile foundations in liquefied soil.