【摘要】 根据地震场地液化特征,将土层分为上部液化土层与下部非液化土层,并基于桩-土相互作用的Winkler模型,将桩等效为Rayleigh梁.建立了考虑上部结构的质量、转动惯量、桩身转动惯量和轴力效应的单桩-土-结构系统的控制方程和边界条件,在频率域给出了问题的解析封闭解.通过与相关实验结果的比较,验证模型和解析解的合理性和有效性,分析几何、物理参数等对单桩-土-结构系统位移放大因子、动力放大因子的影响.研究结果表明:桩身轴力使系统的基频更加趋向地震的主频;土壤的液化使得上部结构动力响应更加剧烈,随着土体液化程度的发展,桩的临界载荷将减小,最终导致桩发生失稳破坏.更多还原

【Abstract】 According to the characteristics of liquefiable soil in earthquake,we divide the liquefiable soil layer into a top liquefied layer and a bottom non-liquefied layer.Based on the Winkler model for the pile-soil interaction and treating the pile as a Rayleigh beam,the governing equations and the corresponding boundary conditions for interaction of the single pile-soil-superstructure are established.This is done by taking into account the mass and inertia moment of the superstructure,and the inertia moment and the axial force of the pile.A closed-form solution is obtained in the frequency domain,of which results are in agreement with experiments.Influences of the geometrical and physical parameters on the displacement amplification factor and the dynamic amplification factor are investigated.It is shown that the axial force drives the first natural frequency of the system to approach the dominant frequency of earthquake.Soil liquefaction increases the system’s dynamic response,and the critical load of the pile decreases with the degree of soil liquefaction,leading to unstable failure of the pile.更多还原