【摘要】 岩石中新生裂隙萌生扩展过程是分析岩石工程性质的重要基础,可以使用颗粒流方法进行研究。本文使用花岗岩室内单轴压缩试验结果标定细观力学性质参数,使用图像处理技术确定花岗岩细观组分的实际分布,通过编制颗粒流代码来确定新生裂隙的类型和萌生扩展过程,分析了岩石变形破坏过程中不同类型新生裂隙变化的阶段性。结果表明,在单轴压缩条件下,花岗岩中新生裂隙萌生时首先出现剪切裂隙、然后出现拉伸裂隙,新生裂隙类型以拉伸裂隙为主;第一条新生剪切裂隙和拉伸裂隙分别出现在石英-黑云母、长石-石英之间;新生拉伸裂隙和剪切裂隙走向分别以331°～340°和以341°～350°为主;在峰值荷载前后新生裂隙扩展表现出明显不同的特点,在峰值荷载之前新生裂隙经受了压密、剪切裂隙增长、拉伸裂隙和剪切裂隙共同增长等阶段,在峰值荷载之后新生裂隙主要经受了拉伸裂隙和剪切裂隙快速增长阶段。本文结果对分析岩石变形破坏机理具有一定的参考价值。更多还原

【Abstract】 The initiation and propagation process of newly-generated micro-cracks in rocks is an important basis for analyzing the engineering properties of rocks which can be investigated using particle flow simulation method. In this study,the meso-scale mechanical properties of the granite were calibrated by the laboratory uniaxial compressive experiment,and the real composition distribution of the meso-components in granite was determined by the image processing technology. The particle flow code was then used to determine the types and the initiation and propagation process of newly-generated micro-cracks. The features of the newlygenerated cracks in various stages during the deformation or failure process in rocks were furthermore explored.The results show that:( 1) under the uniaxial compression load,the most initiated cracks are tensile ones with the firstly-generated shear cracks and following by tensile cracks;( 2) the first newly-generated shear crack occurred between the quartz and biotite,as well as the first newly-generated tensile crack occurred between feldspar and quartz;( 3) the strikes of the newly-generated tensile and shear cracks are 331° to 340° and 341°to 350°respectively;( 4) the propagation of newly-generated cracks shows different features before and after peak load. Before peak load,the newly-generated cracks undergo the stages of compaction,growth of shear crack with increase of tensile and shear cracks,and rapid increase of tensile and shear cracks,while the tensile and shear cracks increase rapidly after peak load. These results will provide certain reference for the analysis of rock deformation or failure mechanism.更多还原