花岗岩微观力学性质试验研究  

Experimental study of micro-mechanical properties of granite

作　　者：张帆[1,2] 郭翰群 赵建建[2] 胡大伟[1] 盛谦[1] 邵建富 

机构地区：[1]中国科学院武汉岩土力学研究所岩土力学和工程国家重点实验室,湖北武汉430071 [2]湖北工业大学土木工程与建筑学院,湖北武汉430068 [3]法国里尔科技大学里尔力学实验室,法国里尔59650

出　　处：《岩石力学与工程学报》2017年第A02期3864-3872,共9页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家自然科学基金资助项目(51579093;51479193);中国博士后科学基金资助项目(2013M531773)~~

摘　　要：为探讨花岗岩的微观力学特性,通过粉晶X射线衍射和光学显微镜的表面观察,获得花岗岩各矿物成分及比例和在显微镜下的表面形貌。然后通过纳米压痕试验,得到荷载–位移曲线和残余压痕,定性分析花岗岩各成分的力学特征,对压痕试验结果统计分析获得各成分的弹性模量和硬度。再通过二次均质化方法得到花岗岩的等效弹性模量和泊松比,并与单轴压缩试验测得的弹性模量及已有研究资料的泊松比进行对比。结果表明:花岗岩主要由石英、长石、云母等成分组成,并能通过颜色、形态特征识别;石英结构致密,力学性质良好,长石次之,云母质地很软,有明显的孔隙结构;均质化方法计算的弹性模量与单轴压缩试验值相差较小,泊松比与已有研究资料基本吻合,其对于评价材料的力学性能有着重要的工程实践意义。研究成果有助于更好地了解花岗岩的微观力学特性,并为从微观角度确定岩石宏观力学性质研究提供参考。In order to study the micro-mechanical properties of granite,the mineral compositions of granite and their proportion were obtained by powder X-ray diffraction experiments,also the surface morphology of granite was observed by optical microscope.Nano-indentation tests were conducted,and then,the load-displacement curves and residual indentation prints were obtained to qualitatively analyze the mechanical properties of the mineral compositions.The elastic modulus and hardness of each component were obtained by statistical analysis of indentation results.A two-step homogenization method was applied to calculate the equivalent elastic modulus and Poisson？s ratio of the granite,which were compared with those obtained by uniaxial compression test and existing research materials respectively.Results show that：the granite is mainly composed of quartz,feldspar and biotite,which can be identified by color and morphological features.The quartz structure is compact and the mechanical properties are good,which is followed by the feldspar,but the biotite texture is very soft and its pore structure is obvious.The difference between the elastic modulus calculated by the homogenization method and that obtained from the uniaxial compression test is relatively small and the Poisson？s ratio is in agreement with the existing data,which has important engineering significance for evaluating the mechanical properties of materials.The results of this study can help to better understand the micro-mechanical properties of granite and provide a reference for the study of macroscopic mechanical properties of rock from a microscopic view.

关 键 词：岩石力学 微观力学性质 纳米压痕试验 矿物成分 

分 类 号：TU45[建筑科学—岩土工程]