基于离散单元法的散体材料桩复合地基变形及承载机理研究

项目名称： 基于离散单元法的散体材料桩复合地基变形及承载机理研究

项目编号： No.51508181

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 建筑科学

项目作者： 谭鑫

作者单位： 湖南大学

项目金额： 23万元

中文摘要： 随着我国基础建设日益增多，在高速公路、铁路等交通基础建设中不免遇到大量不良地基，各种采用散体材料桩作为竖向增强形式的复合地基已成为地基处置技术中的重要手段。然而目前对于散体材料桩的理论研究大多基于连续介质理论，使用宏观力学的研究方法来建立散体材料桩变形和强度的模型，难以准确描述散体材料的离散性与力学非线性。对此，本研究项目结合散体材料颗粒细观结构与宏观力学特性，运用散体颗粒材料理论及研究方法对散体材料桩的细观力链传递、变形破坏规律进行研究，围绕散体材料结构宏细观力学特性、散体颗粒材料试验与离散材料数值模拟方法展开相关研究，并以此为基础深入研究散体材料桩复合地基的变形及承载机理。通过建立宏观应力与散体材料接触力、宏观应变与散体材料位移之间的关系，能更真实地反映散体材料桩复合地基变形失稳机理。该研究将丰富和发展散体材料桩复合地基理论及方法，并能推动散体材料研究方法在各类岩土工程中的相关应用。

中文关键词： 地基加固；复合地基；散体材料桩；颗粒材料；离散单元法

英文摘要： With the rapid development of infrastructure constructions in China, numerous of unfavorable foundations are emerging in various constrictions, especially in highway and high-speed railway infrastructures. The composite ground technic which takes the granular material columns as main reinforced composites thus becomes a crucial method in foundation treatment. However, most research about deformation and bearing capacity of granular material column are carried with continuum theory based on the theory of macro-mechanics. The discreteness and the nonlinear characters in mechanics of granular material are hardly to be described under such hypothesis. To this point, this work tries to investigate the microscopic force chain changes, deformation and failure characteristics of granular material column using the granular material theory and corresponding methods. The deformation and bearing capacity mechanism of composite ground reinforced by granular columns is to be studied through three main parts: the macro-micro mechanical characters of granular material, experiments of granular material and numerical simulation using discrete element method. A more reliable description of deformation and bearing capacity mechanism of composite ground reinforced by granular columns should be presented by establishing the relations between macro-stress and contact force, macro-strain and displacement of discrete particles of granular material. The achievements of this work are able to enrich and develop the theory of composite ground, and also promote the application of granular material theory in various geotechnical engineering problems.

英文关键词： ground reinforcement;composite ground;granular column;granular material;discrete element method