文献类型：期刊文献

中文题名：微裂隙密度对白云岩力学性质影响及其作用机制

英文题名：Mechanisms Controlling and Effect of Microfracture Density on Mechanical Properties of Dolomite

作者：汪权明 穆锐 牛亮

第一作者：汪权明

机构：[1]贵州理工学院土木工程学院,贵阳550003;[2]陆军勤务学院军事设施系,重庆401331;[3]贵州大学土木工程学院,贵阳550025

第一机构：贵州理工学院土木工程学院

年份：2021

卷号：35

期号：2

起止页码：112-120

中文期刊名：重庆理工大学学报：自然科学

收录：CSTPCD;;北大核心:【北大核心2020】；

基金：国家自然科学基金项目(51868009);贵州省科技计划项目([2019]1143);贵州省高层次人才科研启动基金项目;贵州省一流课程项目(YLDX201711)。

语种：中文

中文关键词：天然微裂隙;白云岩;统计分析;SEM电镜扫描;微裂隙密度;破坏机理

外文关键词：natural micro-crack;dolomite;statistical analysis;SEM scanning;micro-crack density;failure mechanism

摘要：为研究原状微裂隙对白云岩力学性质的影响规律,结合实际工程项目对岩层进行钻芯取样,得到原状试样。采用手绘和CAD扫描统计法对微裂隙统计分析,根据微裂隙密度将试样进行分类;通过单轴压缩试验和SEM电镜扫描试验研究微裂隙密度对白云岩微观结构及力学性质的影响机制,得到岩石试样的微裂隙密度范围为0.001 5~0.042 mm/mm^(2),均值为0.024 mm/mm^(2)。研究结果表明:1)在单轴压缩试验中,白云岩力学性质主要由微裂隙"根状"结构控制,试样的破坏分为张拉、剪切和拉剪复合破坏3种类型,应力应变关系为Ⅰ类曲线;2)白云岩的抗压强度和弹性模量随微裂隙密度的增大而减小且微裂隙密度在0.010~0.020mm/mm^(2)范围内变化幅度最为明显;3)随微裂隙倾角的增大,抗压强度先减小后增大,但在微裂隙倾角大于45°时,这种影响作用不明显,呈波动性;4)基于微裂隙密度和微裂隙倾角,分析了白云岩的力学性质影响作用机理,可为类似研究提供基础数据和参考价值。
In order to study the influence of undisturbed micro-cracks on the mechanical properties of dolomite,the undisturbed samples were obtained by core drilling and sampling in combination with practical engineering projects.The statistical analysis of micro-cracks was carried out by hand drawing and CAD scanning statistical methods,and the samples were classified according to the density of micro-cracks.The influence mechanism of micro-crack density on the micro-structure and mechanical properties of dolomite was studied by uni-axial compression test and SEM scanning electron microscope.The results show that the micro-fracture density of rock samples ranges from 0.0015 mm/mm^(2) to 0.042 mm/mm^(2),with an average of 0.024 mm/mm^(2).The results show that:1)in the uni-axial compression test,the mechanical properties of dolomite are mainly controlled by the"root"structure of micro-cracks,and the failure of samples can be divided into three types of tensile,shear and tensile shear composite failure,and the stress-strain relationship is class I curve;2)the compressible strength and elastic modulus of dolomite decrease with the increase of micro crack density,and the micro-crack density is 0.010~0.020 mm/mm2;3)with the increase of micro fracture dip angle,the compressible strength first decreases and then increases,but when the micro-fracture dip angle is greater than 45°,the effect is not obvious and fluctuates;4)based on the micro fracture density and micro-fracture dip angle,the influence mechanism of mechanical properties of dolomite is analyzed,which can provide basic data and reference value for similar research.