【作者】 黄丹；

【导师】 房营光； 汪华安；

【作者基本信息】 华南理工大学 ， 建筑与土木工程， 2012， 硕士

【摘要】 刚性网格—微型群桩复合地基加固法是一种新型的软土地基加固技术,它是由刚性网格与微型桩、过渡垫层、张拉网、软土地基构造在一起组成的。荷载通过刚性网格上压力扩散角的扩散作用传递到刚性网格上，再通过微型桩传递到深层土体中，土工栅格具有协调变形作用和传递一部分荷载至刚性网格上。该复合地基通过网格梁对桩的约束作用不仅可以限制软土层的侧向变形，还可以充分发挥深层土体的强度，从而有效的提高软土地基承载力，与传统复合地基相比的一个显著的优势在于可以很好的控制桩土荷载分担比以达到工程目的。本文作为刚性网格—微型群桩复合地基理论研究中非常重要的一部分，主要通过介绍该复合地基组成结构、加固方法及施工技术，并结合桩—网复合地基的研究成果，对该复合地基用有限元软件进行荷载扩散规律的分析并运用通用有限元分析软件MIDAS/GTS对该复合地基的变形特性和应力扩散规律进行有限元分析，从而得出简单的地基承载力公式，为该复合地基今后试验研究及工程推广打下良好的理论基础。论文的主要工作有：1.分析复合地基的研究现状，针对现有软土地基加固方法存在的缺点，提出一种加固效果好、工期短、成本低的软土地基加固技术（刚性网格—微型群桩复合地基加固法），并介绍该复合地基基本组成结构；2.介绍有限元法的基本原理，构造几何模型并采用有限元软件MIDAS-GTS建立复合地基有限元模型；3.分析桩土模量比、刚性网格刚度、桩间距、长度、张拉网柔度、桩径、垫层厚度等参数对桩土应力比，复合地基的变形性能及承载力的影响规律，以指导工程实践。4.通过以上模型的计算结果和规律得出承载力公式，对工程实践提出适当的建议。更多还原

【Abstract】 Rigid Net Grid-pile group composite foundation as the new way of strengtheningtechnologies for soft clay foundation which consists of rigid gird, micropile structure、transition、subcrust、tension reinforcement net and soft soil foundation Load is applied to thetransition subcrust transferred to the rigid gird,then transferred to deep soil through themicropile groups, and the tension reinforcement net can also transfer some load to the rigidgird. This composite foundation can’ t only restrict the side deformation of soft soil, but alsogive full play to the strength an the deformation properties of the soil by the connect of rigidgird and than strength the soil effectively, comparing with the traditional way which cancontrol the pile-soil stress ratio to complete the project goal.This article as a very important part of the study on properties of the rigid grid-micropilegroups composite foundation, mainly present the rigid grid-micropile groups the way ofreinforcement method and the research result of pile-web composite foundation, then use thetheory of finite element analysis the law of load path in order to gain the formula offoundation bear the weight of load. and lays a good theoretical foundation for futureexperiment research and engineering spread. The major work of this paper is focused onseveral aspects as follows:1. On account of the research actualities of composite foundation and the shortcomingsof soft soil foundation reinforcement currently, this article put forward a good reinforcementeffect, low-cost soft soil foundation reinforcement technique（the rigid gird-micropile groupscomposite foundation reinforcement method）, and describes its main components.2. Introduce the basic principles of the finite element method, build the geometry modeland then use GTS form a FEM model;3. Analyses the impact of the pile-soil modulus ratio, rigid mesh stiffness, pile spacing,pile length, tension network flexibility, pile diameter, subcrust thickness and other parameterson the deformation and the ability of bearing the load of the rigid gird–micropile groupscomposite foundation, then guide the project.4. Through the above model calculation results, find the formula of foundation bear theweight of load and provide some specific suggestions to the project.更多还原