热力耦合作用下无烟煤煤体变形特征的试验研究  

EXPERIMENTAL INVESTIGATION INTO DEFORMATION CHARACTERISTICS OF ANTHRACITE UNDER THERMO-MECHANICAL COUPLING CONDITIONS

作　　者：冯子军[1] 万志军[2] 赵阳升[1] 李根威[2] 张源[2] 王冲[2] 

机构地区：[1]太原理工大学采矿工艺研究所,山西太原030024 [2]中国矿业大学矿业工程学院,江苏徐州221008

出　　处：《岩石力学与工程学报》2010年第8期1624-1630,共7页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家自然科学基金重点项目(50534030);国家自然科学基金资助项目(50874077;50804033);山西省重点实验室基金项目(2009011059-12)

摘　　要：利用自主研制的"600℃20MN伺服控制高温高压岩体三轴试验机"系统,研究φ200mm×400mm大尺寸无烟煤试样在恒定500m原岩应力状态(轴压12.5MPa、围压15MPa),以10℃/h的升温速率从20℃升至600℃过程中的变形规律。试验结果表明:随着温度的升高,无烟煤煤体的变形可分为3个阶段,即20℃～200℃热膨胀阶段、200℃～400℃缓慢压缩阶段和400℃～600℃剧烈压缩阶段。其中,400℃～450℃为无烟煤煤体变形由脆性机制转变为韧性机制的临界温度范围,温度和压力是影响无烟煤煤体变形脆-韧性转变的主要因素,且具有明显的温压等效性,即较高的临界温度所需转化压力较低。热力耦合作用和热解产气是影响煤体变形的关键因素,尤其在高温阶段,热解产气对变形起到主控作用。By utilizing the self developed ＂600 ℃ 20 MN servo-controlled rock triaxial testing machine with high temperature and high pressure＂,the investigation into deformation characteristics of anthracite specimen with 400 mm in length and 200 mm in diameter was carried out at constant stress corresponding to the in-situ stress at the depth of 500 m（axial pressure is 12.5 MPa and confining pressure is 15 MPa）,increasing temperature from room temperature（20 ℃） to 600 ℃ at a rate of 10 ℃/h.The study results indicate that the process of temperature-dependent deformation of anthracite can be divided into three stages,i.e.thermal dilatation stage with temperature rising from room temperature to 200 ℃,slow volume compression stage from 200 ℃ to 400 ℃ and serious volume compression stage from 400 ℃ to 600 ℃.The critical temperature range of anthracite deformation mechanism transition from brittle to ductile is from 400 ℃ to 450 ℃.Temperature and pressure are the main factors which influence the brittle-ductile transition of coal mass.The principle of transition condition is temperature-pressure equivalent,i.e.higher critical temperature needs lower transition pressure.The deformation of coal mass is significantly influenced by thermo-mechanical coupling and pyrolysis gas,while the main factor at a high temperature is pyrolysis gas.

关 键 词：采矿工程 温度 压力 无烟煤 热解 脆-韧性转变 

分 类 号：TD32[矿业工程—矿井建设]