用于动静载下含瓦斯煤损伤机制研究的三轴固气耦合试验仪  

Triaxial solid-gas coupling tester for studying the damage mechanism of gas-bearing coal under dynamic and static loads

作　　者：刘众众 王汉鹏 袁亮[4] 张冰[5] LIU Zhongzhong;WANG Hanpeng;YUAN Liang;ZHANG Bing(State Key Laboratory for Geomechanics and Deep Underground Engineering,China University of Mining and Technology,Xuzhou,Jiangsu 221116,China;School of Mechanics and Civil Engineering,China University of Mining and Technology,Xuzhou,Jiangsuu 221116,China;School of Qilu Transportation,Shandong University,Jinan,Shandong 250061,China;State Key Laboratory of Mining Response and Disaster Prevention and Control in Deep Coal Mines,Anhui University of Science and Technology,Huainan,Anhui232001,China;Geotechnical and Structural EngineeringResearchCentre,ShandongUniversity,Jinan,Shandong250061,China)

机构地区：[1]中国矿业大学深部岩土力学与地下工程国家重点实验室,江苏徐州221116 [2]中国矿业大学力学与土木工程学院,江苏徐州221116 [3]山东大学齐鲁交通学院,山东济南250061 [4]安徽理工大学深部煤矿采动响应与灾害防控国家重点实验室,安徽淮南232000 [5]山东大学岩土与结构工程研究中心,山东济南250061

出　　处：《采矿与安全工程学报》2022年第6期1272-1280,共9页Journal of Mining & Safety Engineering

基　　金：国家重大科研仪器研制项目(52227901);国家自然科学基金面上项目(52174081)。

摘　　要：煤与瓦斯突出是动静荷载叠加作用下含瓦斯煤的损伤破裂动力效应,研究含瓦斯煤的损伤破坏机制对于深化突出机理、破解突出防治难题意义重大。然而,现有仪器只能对含瓦斯煤进行静力加载,与突出煤层的应力场有很大区别。基于此,自主研发了可用于循环动静组合荷载下含瓦斯煤损伤破坏机制研究的三轴固气耦合试验仪。该仪器由动静加载单元、三轴围压单元、流体注入单元和信息采集单元4个关键单元构成,实现了固气耦合环境下煤样动静组合循环加载和损伤破坏过程中声发射参数的精确测试。利用该仪器开展了不同频率循环动载下煤样损伤劣化试验,试验结果表明:循环动载会对含瓦斯煤的宏观力学参数造成损伤劣化,随着循环动载频率的增大,煤样强度和弹性模量的损伤越大,最大损伤劣化率可达30%~40%;煤样三轴压缩过程中声发射与应力-应变曲线呈明显的耦合效应,对应应力-应变曲线,声发射活动可分为平静期、缓增期、动载稳增期和突增期4个阶段;在不同频率的循环动载下,声发射事件峰值的演化规律与累计事件峰值的演化规律不同,随着动载频率的增加,事件峰值减小,累计事件峰值却增大。该仪器采集的声发射参数可以很准确地表征煤样在动载作用下的损伤演化,并和弹性模量损伤量对比,进一步证明了该仪器用于研究含瓦斯煤损伤破坏机制的可靠性。Coal and gas outburst is the damage and dynamic fracture effect of gas-bearing coal under the superposition of dynamic and static loads. Studying the damage mechanism of gas-bearing coal is of great significance in deepening the outburst mechanism and solve the difficult issues of outburst prevention and control. However,the existing instruments can only apply static loading on gas-bearing coal,which is different from the stress field of the outburst coal seam. To this end,a triaxial solid-gas coupling tester,which can be used to study the damage and failure mechanism of gas-bearing coal under cyclic dynamic and static combined loads,is independently developed. The tester is composed of four key units:dynamic and static loading unit,triaxial confining pressure unit,fluid injection unit,and information acquisition unit,enabling the accurate measurement of acoustic emission parameters in the process of dynamic and static combined cyclic loading and damage failure of coal samples under a solid-gas coupling environment. The developed tester is used to conduct the damage and deterioration tests of coal samples under cyclic dynamic loads with different frequencies. The results show that cyclic dynamic load will cause damage and deterioration to the macro mechanical parameters of gas-bearing coal. With the increase of cyclic dynamic load frequency,the damage to coal strength and elastic modulus is greater,and the maximum damage deterioration rate can reach 30%~40%. During the triaxial compression of coal samples,the acoustic emission and stress-strain curve show an obvious coupling effect. Corresponding to the stress-strain curve,the acoustic emission activity can be divided into four stages:quiet period,slow increase period,stable increase period,and sudden increase period. Under cyclic dynamic loads with different frequencies,the evolution law of acoustic emission event peak is different from that of cumulative event peak. With the increase of dynamic load frequency,the event peak decreases while the cumulative event

关 键 词：含瓦斯煤 固气耦合 动静叠加 声发射 损伤演化 

分 类 号：TU45[建筑科学—岩土工程]