压剪复合载荷下煤岩蠕变力学特性及声发射特征

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中文摘要：矿柱轴向与最大主应力方向呈一定夹角分布时,常受到压缩载荷和剪切载荷的共同作用,其力学行为与纯受压矿柱存在显著差异.采用改进的压剪复合加载系统分析了煤岩在压剪复合载荷共同作用下的蠕变力学特性变化规律,结合声发射技术,探究了煤岩微裂纹演化规律和声发射能量特征,总结了不同加载倾角下煤岩力学性能损伤机制.结果表明:随着加载倾角的增加,煤岩峰值强度、蠕变试验总时长、蠕变破坏应力和长期强度总体呈逐渐减小的特征,但蠕变破坏应力和长期强度与峰值强度的比值随倾角变化甚微;煤岩破裂模式由张拉破坏(θ=0°)向剪切破坏(θ=5°,10°和15°)转变;累计声发射能量与其长期强度具有高度相关性,煤柱长期强度越低,其累计声发射能量越小,说明剪切应力分量可使裂纹在较低的能量吸收下扩展;煤岩内部微裂纹的萌生和扩展以及矿物颗粒间摩擦阻力的衰减是导致试样破坏的重要因素.研究结果可为受剪矿柱长期稳定性评估提供重要的理论依据.

外文标题：Creep mechanical properties and acoustic emission characteristics of coal and rock under compressive shear combined load

外文摘要：When the axial orientation of a pillar aligns at a specific angle relative to the direction of maximum principal stress,it invariably experiences a combination of compressive and shear forces,markedly altering its mechanical behavior in contrast to a pillar subjected solely to compression.This in-vestigation employs an enhanced compression-shear combined loading apparatus to scrutinize the creep mechanical properties of coal rock under simultaneous compressive and shear stresses.Employing acoustic emission technology,this research delineates the evolution of micro-cracks and characterizes the acoustic emission energy profiles in coal rock,elucidating the damage mechanisms influencing its me-chanical properties across varying loading angles.Results indicate that with an increasing loading angle,there is a general decline in the peak strength,overall duration of creep tests,creep failure stress,and long-term strength of coal rock;however,the ratio of creep failure stress and long-term strength to peak strength exhibits minimal alteration with the angle.The fracture pattern of coal rock transitions from ten-sile failure at θ=0° to shear failure at θ=5°,10° and 15°.The cumulative acoustic emission energy dem-onstrates a strong correlation with the long-term strength of the structure;a diminution in long-term strength correlates with reduced cumulative acoustic emission energy,suggesting that the shear stress component facilitates crack propagation with less energy absorption.The onset and proliferation of inter-nal micro-cracks in coal rock,coupled with the diminished frictional resistance among mineral particles,constitute critical determinants of sample failure.The findings furnish a substantial theoretical foundation for the evaluation of long-term stability in shear-affected pillars.

外文关键词：

compression shear combined loadcreep characteristicslong-term strengthacoustic emis-sioncrack evolution

作者：

李明、浦海、陈彦龙、吴克通、吴鹏、王岚、岳振

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作者单位：

中国矿业大学深地工程智能建造与健康运维全国重点实验室,江苏徐州 221116

新疆工程学院矿业工程与地质学院,新疆乌鲁木齐 830023

中国矿业大学力学与土木工程学院,江苏徐州 221116

徐州工程学院物理与新能源学院,江苏徐州 221018

徐州工程学院实验室与设备管理处,江苏徐州 221018

山西潞安集团蒲县黑龙煤业有限公司,山西临汾 041204

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关键词：

压剪复合载荷蠕变特性长期强度声发射裂纹演化

基金：

国家重点研发计划项目国家自然科学基金项目国家自然科学基金项目国家自然科学基金项目国家自然科学基金项目新疆维吾尔自治区重大科技专项项目

项目编号：

2023YFC3804204523041025217409052374147419312842023A01002

出版年：

2024

DOI：

10.13545/j.cnki.jmse.2023.0521

采矿与安全工程学报

中国矿业大学中国煤炭工业劳动保护科学技术学会

采矿与安全工程学报

CSTPCD北大核心

影响因子：2.054

ISSN：1673-3363

年,卷(期)：2024.41(4)

参考文献量7