摘要
随煤矿开采深度的不断延深,深部煤体所处的应力环境将逐渐倾向于静水压状态,同时冲击地压、煤与瓦斯突出等典型煤矿动力灾害危害程度不断加大。为研究煤体在不同静水压环境下的动态压缩力学特性,采用主动三轴围压霍普金森压杆试验系统,开展加载率700~1400 GPa/s和3种静水压状态(4 MPa、6 MPa、8 MPa)下煤样动态压缩力学试验研究。研究结果表明:煤样应力应变曲线出现短暂线性弹性阶段,动态弹性模量、动态抗压强度与加载率、静水压限制成正比,动态抗压强度的加载率敏感性与静水压限制成反比;相同加载率下,煤样的破坏应变与静水压大小成正比;冲击加载后煤样宏微观破碎特征表明,随着静水压约束的增强,煤样破碎程度逐渐降低。本研究可为深部煤矿典型动力灾害防灾减灾研究提供参考,对深部煤矿工程布设具有一定的指导意义。
With the deepening of coal mining depth,the stress environment of the deep coal body will gradually tend to the hydrostatic pressure state.At the same time,the damage degree of typical coal mine dynamic disasters such as rock burst,coal and gas outburst is increasing.In order to study the dynamic compressive mechanical characteristics of coal bodies in different hydrostatic environments,the dynamic compression mechanics of coal samples under load rates of 700~1400 GPa/S and three hydrostatic states(4 MPa,6 MPa,8 MPa)were carried out by a split Hopkinson pressure bar(SHPB)system with hydrostatic confinement.The results show that the stress-strain curve of coal sample has a short linear elastic stage.The dynamic elastic modulus and dynamic compressive strength are in direct proportion to the loading rate and hydrostatic pressure limit,and the loading rate sensitivity of dynamic compressive strength is in inverse proportion to the hydrostatic pressure limit.At the same loading rate,the failure strain of coal sample is proportional to the hydrostatic pressure.The macro and micro fracture characteristics of coal samples after impact loading show that the degree of coal sample fracture decreases gradually with the increase of hydrostatic pressure constraint.The study can provide a reference for the research on the prevention and reduction of typical dynamic disasters in deep coal mines,and has a certain significance for deep coal mine engineering.
作者
韩一丹
薛生
程春晖
HAN Yidan;XUE Sheng;CHENG Chunhui(School of Safety Science and Engineering,Anhui University of Science and Technology,Huainan,Anhui 232001,China;Joint National-Local Engineering Research Centre for Safe and Precise Coal Mining Prevention,Huainan,Anhui 232001,China)
出处
《矿业研究与开发》
CAS
北大核心
2022年第12期100-105,共6页
Mining Research and Development
基金
国家自然科学基金重点项目(51934007)
煤炭安全精准开采国家地方联合工程研究中心基金项目(EC2021018)
安徽理工大学研究生创新基金项目(2021CX2034)。
关键词
深部岩石动力学
动态压缩
破坏特征
分离式霍普金森压杆
Deep rock dynamics
Dynamic compression
Failure characteristics
Split Hopkinson pressure bar(SHPB)
