摘要
煤层厚度变异及留设煤柱均可引起顶板-煤体-底板组合体结构变化,在瓦斯浸润-劣化作用下,组合体结构内部微裂隙及弱结构充分发育,破坏难以预测。开展气固耦合条件下不同高比岩-煤-岩组合体单轴加载试验,系统分析其力学特性、破坏特征以及声发射响应规律。研究结果表明:瓦斯劣化了组合体整体强度,加强了“界面效应”对于砂岩的弱化作用,减弱了“界面效应”对煤的强化作用;煤岩体阶段Ⅰ(0<σ0<1/4σ_(max)),裂纹被压实,声发射振铃计数较少,阶段Ⅱ(1/4σ_(max)<σ0<1/2σ_(max)),声发射振铃计数稳步增加,峰值频率呈高频低幅,阶段Ⅲ(1/2σ_(max)<σ0<3/4σ_(max)),裂隙增生、扩展,峰值频率呈中频中幅,频段由高到低逐渐减少甚至消失,阶段Ⅳ(3/4σ_(max)<σ0<σ_(max)),振铃计数在峰后阶段出现“二次峰值”点后,煤岩发生宏观破坏,峰值频率呈低频高幅;随着煤厚增加,组合体拉伸破坏占比平均值分别为91.92%,83%和76.17%,脆性减弱,塑性增强,裂纹倾角增大,宏观破坏形态由“X”形向“Y”形共轭破坏转变。研究结果为揭示深部含瓦斯煤层灾变失稳机理及防治深部煤岩瓦斯复合动力灾害提供了基础理论指导。
Both the variations in coal seam thickness and the retention of coal pillars can cause structural changes in the roof-coal-floor combination.Under the influence of gas infiltration and deterioration,mi-cro-fractures and weak structures within the combination develop extensively,making the prediction of failure challenging.In this study,uniaxial loading tests were performed on rock-coal-rock combinations with different height ratios under gas-solid coupling conditions.Based on the test results,a systematic analysis was conducted on their mechanical properties,failure characteristics,and acoustic emission(AE)response patterns.The research results indicate that gas deteriorates the overall strength of the combination,enhances the weakening effect of the"interface effect"on sandstone,and diminishes the strengthening effect of the"interface effect"on coal.In Stage Ⅰ(0<σ0<1/4σ_(max)),cracks in the coal-rock combination are compacted,so that the AE ring counts are relatively low.In Stage Ⅱ(1/4σ_(max)<σ0<1/2σ_(max)),the AE ring counts increase steadily,and the peak frequency is characterized by a high value and a low amplitude.In Stage Ⅲ(1/2σ_(max)<σ0<3/4σ_(max)),cracks proliferate and propagate.Correspondingly,the peak frequency shows a medium value and a medium amplitude,and the frequency band gradually declines and even disappears.In Stage Ⅳ(3/4σ_(max)<σ0<σ_(max)),the combination undergoes macroscopic failure after a"secondary peak"of AE ring counts appears in the post-peak stage.In this case,the peak frequency features a low value and a high amplitude.As the coal thickness increases,the average proportion of tensile failure in the combination is 91.92%,83%,and 76.17%,respectively.Such changes mark a reduction of brittleness,an enhancement of plasticity,a growth of crack inclination angles,and a transition of macroscopic failure mode from an"X-type"to a"Y-type"conjugate failure.The research results can provide a fundamental theoretical reference for revealing the mechanism of catastrophic instability in deep gas-bearing coal seams and offer basic theoretical guidance for the prevention and control of deep coal-rock-gas composite dynamic disasters.
作者
郭鹏慧
杨科
李家卓
池小楼
刘文杰
吴向辉
GUO Penghui;YANG Ke;LI Jiazhuo;CHI Xiaolou;LIU Wenjie;WU Xianghui(Key Laboratory of Safe and Effective Coal Mining Ministry of Education,Anhui University of Science&Technology,Huainan,Anhui 232001,China;State Key Laboratory of Safe Mining of Deep Coal and Environmental Protection,Anhui University of Science&Technology,Huainan,Anhui 232001,China;School of Mining Engineering,Anhui University of Science&Technology,Huainan,Anhui 232001,China)
出处
《采矿与安全工程学报》
北大核心
2025年第4期960-970,共11页
Journal of Mining & Safety Engineering
基金
国家自然科学基金区域创新发展联合基金重点项目(U21A20110)
国家重点研发计划项目(2023YFC2907502)
安徽省高校优秀科研创新团队项目(2024AH010009)
煤矿安全高效开采省部共建教育部重点实验室研究生开放基金项目(JYBSYS202406)
安徽省研究生学术创新项目(2024XSCX076)
安徽理工大学研究生创新基金项目(2023CX1005)。
关键词
气固耦合
瓦斯
岩-煤-岩组合体
单轴压缩
声发射
gas-solid coupling
gas
rock-coal-rock combination
uniaxial compression
acoustic emis-sion
作者简介
郭鹏慧(1996-),男,山西省大同市人,博士研究生,从事煤岩瓦斯动力灾害监测预警与防治方面的研究;通信作者:杨科,E-mail:yksp2003@163.com,Tel:0554-6632995。
