首页|不同碎裂程度岩体三轴压缩力学特性及破坏特征

不同碎裂程度岩体三轴压缩力学特性及破坏特征

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深部开采条件下地质条件劣化,破碎岩体很容易出现大变形破坏问题.本文利用 3DEC软件中离散断裂网络(DFN),建立考虑地下深部不同碎裂程度的合成岩体(SRM)模型,开展了围压加载条件下高应力碎裂岩体的力学特性研究,建立了岩体完整性系数与抗压强度和弹性模量关系式.试验结果表明:碎裂程度较大的岩体,在单轴压缩试验中表现出较强的延性破坏特征;同一碎裂程度岩体随加载围压增大,围岩应力—应变曲线在屈服阶段的抗压强度和塑性变形显著增大,峰后应力跌落幅度变缓;岩体内部微裂隙最先萌生于节理面端部及其交汇部位,节理数量越大裂纹发展、贯通越快;高围压加载时,岩石模型试样破坏模式由张拉破坏向剪切滑移破坏转变.碎裂岩体破坏特征和其碎裂程度与应力加载环境紧密相关,是工程施工与设计的重要参考依据.
Mechanical Properties and Failure Characteristics of Rock Masses with Different Degrees of Fragmentation under Triaxial Compression
Under deep mining conditions,geological conditions deteriorate,and fractured rock masses are prone to large deformation and failure.The discrete fracture network(DFN)in 3DEC software is applied to establish a synthetic rock mass(SRM)model considering different degrees of fragmentation in deep underground areas.The mechanical properties of high-stress fractured rock masses under confining pressure loading conditions are studied,and the relationship between rock integrity coefficient,compressive strength,and elastic modulus is established.The experimental results show that rock masses with a high degree of fragmentation exhibit strong ductile failure characteristics under uniaxial compression tests;As the confining pressure increases,the compressive strength and plastic deformation of the stress-strain curve at the yield stage significantly increase with the same degree of fragmentation,and the amplitude of post-peak stress drop slows down;The micro cracks inside the rock mass first originate at the end of the joint surface and its intersection,and the larger the number of joints,the faster the crack development and connection;When subjected to high confining pressure loading,the failure mode of the specimen changes from tensile failure to shear slip failure.The failure characteristics of fractured rock masses are closely related to their degree of frag-mentation and the stress-loading environment,which is an important reference for engineering construction and design.

deep miningfractured rock masstriaxial compressionmechanical propertiesdiscrete fracture network

张杰、顾秀华、熊赞民、温震江、王筱添

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中国恩菲工程技术有限公司,北京 100038

长沙矿山研究院有限责任公司,湖南 长沙 410012

深部开采 碎裂岩体 三轴压缩 力学特性 离散断裂网络

中国博士后科学基金项目

2022M723524

2024

金属矿山
中钢集团马鞍山矿山研究院 中国金属学会

金属矿山

CSTPCD北大核心
影响因子:0.935
ISSN:1001-1250
年,卷(期):2024.(4)
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