颗粒状岩土材料在临界状态下的剪切机理与抗剪强度研究

项目名称： 颗粒状岩土材料在临界状态下的剪切机理与抗剪强度研究

项目编号： No.51209237

项目类型： 青年科学基金项目

立项/批准年度： 2013

项目学科： 水利科学与海洋工程学科

项目作者： 戴北冰

作者单位： 中山大学

项目金额： 25万元

中文摘要： 颗粒状岩土材料作为一种典型的离散介质，其剪胀行为相当复杂。基于连续介质力学的传统研究使学者们对其特殊剪胀状态－临界状态及其相关理论产生了不同的理解，尤其对颗粒状岩土材料在临界状态的剪切机理与抗剪强度的认识还存在明显的分歧。本项目拟针对颗粒状岩土材料的离散性，研究颗粒基本性质，如颗粒大小、形状、颗粒间摩擦等，对其在临界状态下的力学行为和抗剪强度的影响，主要研究包括：（1）通过试验研究颗粒基本性质对临界状态下的宏观剪切行为和抗剪强度的影响；（2）通过数值模拟从细观上分析颗粒基本性质对临界状态下细观结构和颗粒细观运动的影响规律；（3）建立临界状态细观力学模型并推导临界状态抗剪强度表达式。本项目旨在通过这些研究来从根本上揭示颗粒状岩土材料在临界状态的剪切机理，阐明临界状态抗剪强度的物理意义，为丰富和完善土的临界状态理论与抗剪强度理论提供重要的试验与理论支持，为土的宏观本构模型微观化奠定坚实的基础。

中文关键词： 颗粒土；临界状态；剪胀；颗粒基本性质；离散性

英文摘要： Granular soil, as a typical kind of discrete media, exhibits rather complex shear and dilatancy behaviors. Nevertheless, conventional studies which are founded upon continuum mechanics theories have led to misunderstandings among researchers, in respect of the special dilatancy state－critical state and its related theories. In particular, there remain some evident divergences in understanding the essential shearing mechanism and shear strength at critical state for granular soil. By focusing on the discrete nature of granular soil, this research project presents an investigation into the effect of basic particle attributes which primarily refer to particle size, particle shape, inter-particle friction, etc., on the mechanical behavior and shear strength of granular soil at critical state. The main research works include: (1) the experimental study on the effect of basic particle properties on the macroscopic shear behavior and shear strength at critical state; (2) the numerical examination from a microscopic perspective into the influence mechanism of basic particle attributes on the microstructures and microscopic particle motions at critical state; (3) the establishment of a micromechanical model of critical state and the derivation of a mathematical expression of critical state shear strength. These investiga

英文关键词： granular soil；critical state；stress-dilatancy；basic particle property；discrete nature