弱胶结地层条件下垮落带岩层破碎冒落特征与压实变形规律试验研究

采空区顶板岩层的破碎、冒落、压实、类固结等性能是影响垮落带高度变化的重要因素。通过破碎岩石压缩实验和岩石崩解实验,研究了不同类型岩石的破碎、崩解性能,分析了岩石膨胀变形—破碎冒落—充填压实—蠕变固结的变形过程及特征,揭示了我国东部和西部矿区岩石变形破坏的差异性。研究结果表明:弱胶结岩石具有强碎胀、易崩解的特性,西部弱胶结岩石较中东部岩石更易破碎,耐崩解指数较中东部岩石偏小,岩石耐崩解指数随崩解循环次数增加呈线性递减关系;相同采高条件下,西部弱胶结地层工作面初始垮落带高度较中东部岩层工作面小,弱胶结地层工作面垮落带趋于稳定后垮落带高度的变化量大,弱胶结岩石的胶结性越差这种特性越强。相似模拟试验结果证明了理论分析的可靠性。

Experimental study on characteristics of broken caving and regularity of compaction deformation of rocks in caving zone in the weakly cemented strata

The rocks properties of broken,caving,compaction,consolidation are important influence factors on the height variation of caving zone.Based on the broken rocks compression experiment and rocks disintegration experiment,the different types of rock broken and disintegration properties were studied,the rock time deformation characteristics and process of swelling deformation and broken caving and filling compaction and consolidation were analyzed,the differences between rock deformation and failure were revealed in Western and Eastern China.The results show that the weakly cemented rock has the characteristics of strong expansion and easy disintegration,weakly cemented rock is easily broken than the Middle Eastern rock,resistant disintegration index of weak cemented rock is smaller than Middle Eastern rock,The relationship of the disintegration index of the rock was linear decreasing with the increase of the number of disintegration cycles;under the same mining height condition,the initial height of caving zone of work face in the weakly cemented strata is smaller than in Middle Eastern areas,the variable quantity of caving zone height is larger after caving zone tends to be stable for weakly cemented strata work face,the characteristic is stronger if cementation of cement rock is poorer.The results of similar simulation experiment also proved the reliability of this theoretical analysis.