【摘要】 岩土类颗粒物质在自然界、工程建设以及日常生活中普遍存在,其运动特性的研究在力学界已经开展了几十年.在近20年开展的一系列小尺寸物理实验中,颗粒物质表现出许多新奇现象,人们从物理角度开展了系统研究,在统计力学中,颗粒固体的流体动力学等理论研究以及实验检测技术等方面都取得突破性进展,深刻地揭示了颗粒材料的物理机制,促使力学界对颗粒物质研究中原有的概念、假设、模型和理论进行重新认识.本文主要介绍颗粒物质的细观结构特点,以Rowe应力剪胀关系为例的宏细观研究思路,非线性、非弹性本构关系的细观推导,宏观强度与颗粒摩擦系数的关系,尺寸效应和相似关系等基础问题,介绍了岩土颗粒力学的新进展,介绍了常用的实验量测手段.基于我们的经验,提出了今后需要加强的几个方面:如分析颗粒离散元理论和计算细节;开展理想实验来验证理论和计算结果;结合迅速发展的高性能计算能力,开展高科学置信度大规模计算.目前,岩土类颗粒物质的宏细观研究尚处于起步阶段,到达实际工程应用还有很长的路要走;相关的工程技术要取得实质进展,还需依赖颗粒物质等基础研究的突破.更多还原

【Abstract】 A granular material is a conglomeration of discrete solid,macroscopic particles characterized by a loss of energy whenever the particles interact.Granular materials are omnipresent in nature,industrial practice and daily life,with size spanning from 1μm to a few meters.The mechanical properties have long been studied. In recent two decades,many laboratory scale tests have been conducted and novel phenomena were observed. Both theoretical studies,such as granular matter statistical mechanics,granular solid hydrodynamics,and measurement techniques,such as X-ray CT,photoelastics,have witnessed great breakthrough.The revealed physical mechanism prompt ones to examine the assumptions,concepts,models and theories that previously proposed and being used.In this review paper,major fundamental problems are presented introduced and discussed,including the characteristics of microscale structure,procedure of micro-macro study with Rowe stress dilatancy relation as an example,derivation of stress and strain from microscale structure,the relation of macroscale strength with particle friction,size effect and similarity.In addition,granular soil as a typical granular material,its new developments are summarized.The frequently used techniques are introduced as well. Finally,we present a few aspects in which research should be reinforced,such as examining the assumptions in the discrete element method and checking the computing details,conducting the ideal physical and numerical experiments;by lying on the fast development of high performance computing,carrying on high scientific confidence degree large scale computation of granular materials with high scientific confidence degree;with the help of fast development of high performence computers.The mechanics of granular materials is still at its infancy stage,and there is a long way to directly solve the engineering problems.Essential development of related engineering technologies depends certainly on progress or break-through in the of fundamental studies of granular material mechanics.更多还原