煤层自燃防治与高温爆破安全技术中的若干力学问题  

Several Mechanical Problems on Prevention of Spontaneous Combustion of Coal and Safety Controlling in High-temperature Blasting

作　　者：李世海[1] 王理想[1] 冯春[1] 郑炳旭[2] 李战军[2] 

机构地区：[1]中国科学院力学研究所,北京100190 [2]广东宏大爆破股份有限公司,广州510623

出　　处：《爆破》2015年第3期1-9,16,共10页Blasting

基　　金：中国科学院战略性先导科技专项(XDB10030303);国家自然科学基金项目(51374196);国家自然科学基金青年基金项目(11002146;11302229)

摘　　要：煤层自燃已经是我国大规模煤矿开采不可回避的问题。在高温环境下的煤矿爆破开采,既涉及到爆破的高温环境也需要改进高温爆破技术,其中认识高温爆破中的工程规律,是解决高温爆破技术的关键。首先对煤层自燃的条件进行了量纲分析,说明了煤层中裂隙对流比热传导更容易诱发煤层自燃;煤体中的破裂场、气流场是煤层自燃的条件,单纯封堵裂缝隔绝空气的方法有短期效果,但地质体因煤层燃烧力学特性改变产生变形和破裂后,会死而复燃。讨论了井工开采诱发煤层自燃的机理以及相关科学问题,对井工开采分析了采空区上方冒落带、破裂带、沉降带与煤层自燃的关系,提出了地表长期封闭覆盖与自适应循环注水相结合的综合灭火方法。进而分析了露天矿开采高边坡稳定性与煤层自燃环境的关系,边坡开挖引起山体变形、开裂,形成破裂场是产生煤层自燃的基本要素。最后,分析了深孔爆破中,爆破技术可靠性中涉及的科学问题,介绍了利用循环水降温的方法。Spontaneous combustion of coal has been an inevitable problem in large-scale coal mining in China. Mine blasting under high temperature involves not only the high temperature environment itself,but also the improve- ment of high-temperature blasting technology. The understanding of engineering regulations is the key to improving high-temperature blasting technology. Firstly, the paper performs dimensional analysis on spontaneous combustion conditions of coal. The analysis shows that convective heat transfer in fracture is more likely to cause spontaneous combustion of coal than heat conduction. The fractures and air in coal are necessary conditions. Although the method of blocking fractures to insulate the air makes short-term effects, the combustion of coal will start again after deforma- tion and cracking due to changes of mechanical properties of coal. The mechanisms and scientific problems on spon- taneous combustion in terms of underground mining are also discussed. The relationship is pointed out between caving zone, fracture zone, sedimentation zone and spontaneous combustion of coal. A method combining long-period ground sealing and covering with adaptive cycled water injection is proposed to prevent spontaneous combustion of coal. Sec- ondly, the relationship is analyzed between high slope stability in opencast mines and spontaneous combustion envi- ronment. Slope excavation causes deformation and cracking of rock ,forming fracture field which is necessary for spon- taneous combustion. Finally, some scientific problems involved in blasting technology reliability and cooling methodwith cycled water are analyzed in deep-hole blasting.

关 键 词：煤层自燃 高温爆破 量纲分析 连续-非连续单元法(CDEM) 数值模拟 防治措施 

分 类 号：O389[理学—流体力学]