【摘要】 为研究徐庄矿承压水体上近距离煤层上位7199工作面开采后对下位8199工作面采前底板岩体的损伤程度,将该矿8199工作面和姚桥矿7265工作面底板岩体进行对比,采用钻孔超声探测、岩芯室内超声透射及点载荷试验方法进行研究。研究表明:岩体弹性模量与岩体密度、岩性及完整性呈非线性正相关关系。徐庄矿8199工作面底板浅部砂质泥岩、砂岩受顶煤采动影响,损伤程度大,已散失原有的承载能力;中部完整泥岩段未受顶煤采动及逆断层影响,损伤程度弱;底部泥岩及灰岩段受逆断层影响严重,原始损伤程度大。力学试验验证了室内外声波测试结果的准确性,建立了泥岩、砂岩损伤前后强度—弹性模量数学关系式。分析成果对于相似条件下煤层底板破坏深度预计及工作面底板防治水等方面具有一定的参考意义。更多还原

【Abstract】 In order to study the damage degree of floor rock mass before the lower 7199 working face is mined and after the upper 8199 working face is explored for close-distance coal seam above confined water body of Xuzhuang Mine,the floor rock mass at 8199 working face of the mine and 7265 working face of Yaoqiao Mine are compared and studied by borehole ultrasonic detection,core indoor ultrasonic transmission and point load experiment.The study results show that the elastic modulus of rock mass is positively correlated with the density,lithology and integrity of rock mass.The shallow sandy mudstone and sandstone of Xuzhuang 8199 working face floor are affected by top coal mining,with large damage degree,which makes it lose the original bearing capacity;the complete mudstone section in the middle is not affected by top coal mining and reverse fault,with weak damage degree;the mudstone and limestone section in the bottom is seriously affected by reverse fault,with large original damage.Mechanical experiments verify the accuracy of indoor and outdoor acoustic testing results,and establish the mathematical relationship between strength and elastic modulus of mudstone and sandstone before and after damage.The above study resutls can provide certain reference significance for the prediction of the failure depth of coal seam floor and water prevention and control of the floor of working face.更多还原