SH波作用下液化土中桩-土-上部结构的动力相互作用

发布时间：2018-01-30 14:28

本文关键词： SH波液化土桩-土-结构相互作用 Winkler模型动力特性解析解　出处：《工程力学》2017年01期 　论文类型：期刊论文

【摘要】：以桩-土相互作用的Winkler模型为基础,将桩等效为Timoshenko梁,上部结构等效为刚性质量块,研究了桩基底土体承受垂直入射简谐SH波作用的液化土层中桩-土-上部结构系统的动力特性。考虑土体的自由场位移以及上部结构质量、转动惯量和桩轴向压力的二阶效应,建立了液化土层中单桩-土-刚性上部结构系统的边值问题,并利用分离变量法得到桩变形的解析解。在验证理论模型和解析解合理性和有效性的基础上,分析了几何和物理参数等对桩头位移放大因子和动力放大因子的影响,研究结果表明:单桩-土-上部刚性结构系统存在明显的共振现象,且土体自由场位移对桩头位移放大因子影响显著。随着土体液化程度的发展,单桩-土-刚性上部结构系统基频、桩头动力放大因子和桩失稳临界荷载逐渐减小。
[Abstract]:Based on the Winkler model of pile-soil interaction, the pile is equivalent to a Timoshenko beam, and the superstructure is equivalent to a rigid mass block. The dynamic characteristics of pile-soil-superstructure system in liquefaction soil under vertical incident harmonic SH wave are studied. The free field displacement of soil and the mass of superstructure are considered. The boundary value problem of a single pile-soil-rigid superstructure system in liquefaction soil is established by the second order effect of the moment of inertia and the axial pressure of the pile. The analytical solution of pile deformation is obtained by using the method of separating variables, and the rationality and validity of the theoretical model and the analytical solution are verified. The effects of geometric and physical parameters on displacement amplification factor and dynamic amplification factor of pile head are analyzed. The results show that there is obvious resonance phenomenon in the single pile-soil-upper rigid structure system. With the development of soil liquefaction degree, the fundamental frequency of single pile-soil-rigid superstructure system is obvious. The dynamic magnification factor of pile head and the critical load of pile instability gradually decrease.
【作者单位】：上海大学土木工程系;
【分类号】：TU435
【正文快照】： 桩作为深基础中最常见的结构形式,能较好适应复杂地质条件及各种荷载,具有降低基础沉降、提高承载力和抵抗复杂荷载等优点[1 2]。随着桩基工程的发展和地震资料的丰富,在当今的土木及相关工程领域,非液化土与桩的动力相互作用研究已取得了丰富的成果,建立了较为完整的理论和

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