岩石裂纹闭合效应及其定量模型研究  

A study of crack closure effect of rocks and its quantitative model

作　　者：彭俊[1,2] 荣冠[1,2] 周创兵[1,3] 彭坤[4] 

机构地区：[1]武汉大学水资源与水电工程科学国家重点实验室,湖北武汉430072 [2]武汉大学水工岩石力学教育部重点实验室,湖北武汉430072 [3]南昌大学建筑工程学院,江西南昌330031 [4]中船第九设计研究院工程有限公司,上海200063

出　　处：《岩土力学》2016年第1期126-132,共7页Rock and Soil Mechanics

基　　金：国家自然科学基金(No.51579189);国家973项目(No.2011CB013501);教育部新世纪优秀人才计划项目资助(No.NCET-11-0406)~~

摘　　要：岩石的裂纹闭合效应对于岩石的变形以及强度性质具有重要影响。主要研究了岩石内部微裂纹的闭合压密效应及其定量评价方法。首先,基于有效介质理论将岩石的轴向应变分为基质轴向应变和裂纹轴向应变两部分;然后通过3组岩石压缩试验资料,建立裂纹轴向应变随轴向应力变化的负指数模型。分析发现,负指数模型可以较好地描述岩石裂纹闭合压密阶段的非线性。裂纹闭合应变可以在一定程度上反映岩石内部的微裂纹数量(密度),能够描述微裂纹密度在单轴、三轴压缩条件下的变化规律。The deformation and strength of rocks are significantly influenced by the crack closure behavior. In this study, the crack closure effect and its quantitative characterization are studied. First, based on the widely used effective medium theory, the axial strain is divided into the matrix axial strain and the crack axial strain. Three sets of test data are then used to establish a negative exponential model for the relationship between the crack axial strain and the axial stress. It is found that the crack closure behavior is well captured by the proposed model. The crack closure strain can be used to some extent to represent the microcrack quantity（or microcrack density） in the rock sample. The variation of the microcrack density under uniaxial and triaxial compressions is well described by using the crack closure strain.

关 键 词：裂纹闭合效应 有效介质理论 微裂纹损伤 压缩试验 

分 类 号：TU473.1[建筑科学—结构工程]