【作者】 韩勇；

【导师】 葛克水；

【作者基本信息】 中国地质大学（北京） ， 地质工程， 2006， 硕士

【摘要】 作为近些年兴起的一个引起世界重视的新课题,桩-土体系相互作用动态分析的研究一直都以线性分析为主,而对非线性和弹塑性分析较少;另外在对群桩-土体系的相互作用分析上,更多的则是通过经验来总结其内部应力、应变规律,而对群桩内部应力、应变的相互关系的微观分析还不够。随着计算机技术的发展,使得短时间计算大规模数据成为了现实。本文就是针对桩-土体系研究现状中存在的以上两个问题,采用有限元法对桩-土模型进行地震水平荷载下的动态分析。建模过程中,文中首先确定了桩-土体系的本构模型和相互作用分析模型,之后着重解决了土体边界的问题,最后建立了纯土体、单桩-土体、两桩-土体和三桩-土体四个模型。求解过程主要以谱分析和地震波瞬态响应分析为主,针对同模型中不同节点和不同模型中同区域节点的 x、y 方向位移(Ux、Uy)、x 方向应力(Sx)关系进行分析,得到了大量的图形和数据,通过筛选并对比分析,最终得到了以下主要结论:1、同一模型下,同一水平方向上不同节点 Ux随时间变化几乎相同;2、同一模型下,相对外部土体而言,桩对桩间土 Uy产生了减小的作用;3、同一模型下,同水平方向上节点 Sx 表现为以 y 轴为对称轴,大小相等,方向相反;4、通过单桩-土体模型分别与两桩-土体模型和三桩-土体模型 Ux、Uy、Sx的对比,证明了群桩效应的产生,并得到了群桩 Ux、Uy、Sx的变化特点;5、随着桩数量的增加,得到了桩间土、桩外土体、和桩身上节点 Ux、Uy 和 Sx的变化规律。更多还原

【Abstract】 As a new subject arisen in these years, the research of dynamic analysis on pile-soilsystem is valued by the whole world. But most of the methods of the analyses is linear andthere are few of non-liner & elastic-plastic methods. On the other hand, the conclusion ofanalyses on pile groups-soil are mostly depended on the experience. And there are notenough micro-analyses on the displacement and strain inside the pipe group.With the development of computer technology, it is valuable to make big calculationin a shout time. Aimed at the two problems mentioned above, the paper analyses thedynamic & seismic analysis on pile-soil system with finite element method.During the period of setting up models, the paper set the constitutive model anddynamics behavior model of pile-soil system first. And then settled the problem on the soilboundary and the conjunction between soil and pile. At last four models were set: soilonly, one pile-soil, two piles-soil and three piles-soil.With the methods of spectrum analysis and earthquake transient response,towardswith the different nodes in a same model and a same node in different models, the papercarried on analysis to research the displacement of x,y-direction and the strain ofx-direction. And at last I got a lot of figures and data. By sifting and comparing the figuresand data, the following results were got:1、The Ux of the nodes in same level direction is unchanged in one model.2、Compared with the soil outside the piles, the piles reduced the Uy of the soilbetween piles in one model.3、The Sx of the nodes in same level of the same model is symmetric byY-coordinate.4、Proved the appearance of the efficiency of pile groups and together got thecharacter of the changing of Ux,Uy and Sx by comparing with the four modelsmentioned above.5、With the increase of the number of piles, I got the law of the changing on the Ux,Uy and Sx of a same node: in soil outside the piles, in the soil among the pilesand inside the pile.更多还原