本科毕业设计论文--不同地基模型上筏形基础的有限元分析 .doc

郑州大学本科毕业论文 题 目： 不同地基模型的分析 指导教师： 职称： 副教授 学生姓名： 学号： 2000420316 专 业： 土木工程 院（系）： 土木工程学院 完成时间： 201年 月日 摘 要 筏板基础是一种常用的基础形式，不同的地基模型对筏板的应力、应变、位移都有很大的影响。根据实际情况，选择合适的地基模型，有助于使筏板和地基土的计算更符合实际情况，使工程更好的兼顾安全与经济。 本文采用ABAQUS有限元软件，对筏板基础进行了有限元分析，主要研究了以下内容：筏板在弹性半空间地基模型中考虑土的弹塑性时，其沉降情况将土体简化成Winkle地基模型时，分析比较了基础沉降变形的差异性，并基于Winkle地基模型，讨论基础沉降及受力随筏板刚度变化的规律最后，为分析土体的蠕变特性，研究了筏板在粘弹性地基模型上的沉降变形。结果表明：筏板的变形是由整体变形和局部变形叠加的结果，整体变形决定了基础的沉降，局部变形决定了应力的分布；Winkle地基模型将土体做了很大的简化，其参数很少，所以使用该模型时要慎重考虑条件；仅考虑基础与土体相互作用时，基础内力随其刚度增大而增大，相对挠曲随之减小，但上部结构刚度对基础沉降的影响作用是有限度的；对于蠕变特性明显的地基，设计时应重视筏板加载完成并稳定之后的沉降和差异沉降。 关键词：筏板基础、有限元、地基模型、沉降受力分析 Abstract Raft foundation is one of the most widely used base forms nowadays, and different subsoil models adopted in the design may have great impact on the calculating results of stress, strain, displacement, etc, of the raft foundation. So it is of great significance to choose the suitable subsoil model according to the actual conditions, which can help to make the calculations of the raft foundation and subsoil more realistic, reaching a better balance between safety and economy of the actual project. The finite element software ABAQUS is used to analysis the raft foundation. The topics discussed in this paper are as follows: the settlement of the raft foundation is calculated in the elastic half-space subsoil model taking elastoplasticity into consideration; when the soil mass is simplified into Winkle subsoil model, the differences between the settlement of the same foundation in two kind of the groundsill is studied, and the changing rule of the foundation’s subsidence which has relationships with the changes of raft foundation’s stiffness is studied based on Winkle model too. At last, in order to analysis the character of creep in soil, the deformation and settlement of raft foundation in viscoelastic subsoil model is studied. The calculating results show that: the deformation of t