间距对上保护层开采保护效果影响的相似模拟实验研究
发布时间：2018-10-26 17:41
【摘要】：为研究上保护层开采保护效果随层间距的变化规律,以南桐矿区作为实验背景,保持保护层倾向工作面开挖长度、煤层埋深、倾角、岩层物理力学性质相同,将层间多层岩层处理为复合岩层,分别进行近距离、远距离和超远距离上保护层开采相似模拟实验。综合分析被保护层卸压规律及基于被保护层垂直于层面的膨胀变形保护准则所得保护范围可知:上保护层开采被保护层卸压曲线呈"凸形",且"凸形"中心线偏向下山方向。随层间距增加,"凸形"底部被保护层小于原岩应力的卸压范围与"凸形"顶部卸压曲线顶部较大卸压的范围均呈减小趋势;两者中心位置均向下山方向转移,且后者转移度大于前者;被保护层卸压曲线中卸压范围的卸压程度及应力集中范围的应力集中程度均呈减弱趋势;以垂直层面的膨胀变形量3‰确定的上下边界膨胀变形保护角均小于《防治煤与瓦斯突出规定》中相应条件的卸压角,因此以该方法确定的保护范围相对《防治煤与瓦斯突出规定》偏于安全,且随层间距增加保护范围长度呈加速减小趋势。
[Abstract]:In order to study the variation of the protective effect of the upper protective layer with the interval between the layers, taking Nantong mining area as the experimental background, the length of the protective layer inclined to the working face, the depth of the coal seam, the inclination of the coal seam, and the physical and mechanical properties of the strata are kept the same. The interlayer multi-layer strata are treated as composite strata, and the simulation experiments are carried out for the exploitation of protective strata in short distance, long distance and over long distance respectively. Based on the comprehensive analysis of the pressure relief law of the protected layer and the protection range based on the expansion deformation protection criterion of the protected layer perpendicular to the layer, it can be seen that the relief curve of the protected layer in the mining of the upper protective layer is "convex", and the "convex" centerline is inclined to the downhill direction. With the increase of the interval between layers, the pressure relief range of the "convex" bottom protected layer is smaller than that of the original rock stress, and the larger pressure relief range at the top of the "convex" top pressure relief curve shows a decreasing trend. Both of them are moving downhill, and the latter is larger than the former, and the pressure relief range and the stress concentration of the stress concentration range in the pressure relief curve of the protected layer tend to weaken. The upper and lower boundary expansion deformation protection angle determined by 3 鈥，
本文编号：2296479
[Abstract]:In order to study the variation of the protective effect of the upper protective layer with the interval between the layers, taking Nantong mining area as the experimental background, the length of the protective layer inclined to the working face, the depth of the coal seam, the inclination of the coal seam, and the physical and mechanical properties of the strata are kept the same. The interlayer multi-layer strata are treated as composite strata, and the simulation experiments are carried out for the exploitation of protective strata in short distance, long distance and over long distance respectively. Based on the comprehensive analysis of the pressure relief law of the protected layer and the protection range based on the expansion deformation protection criterion of the protected layer perpendicular to the layer, it can be seen that the relief curve of the protected layer in the mining of the upper protective layer is "convex", and the "convex" centerline is inclined to the downhill direction. With the increase of the interval between layers, the pressure relief range of the "convex" bottom protected layer is smaller than that of the original rock stress, and the larger pressure relief range at the top of the "convex" top pressure relief curve shows a decreasing trend. Both of them are moving downhill, and the latter is larger than the former, and the pressure relief range and the stress concentration of the stress concentration range in the pressure relief curve of the protected layer tend to weaken. The upper and lower boundary expansion deformation protection angle determined by 3 鈥，
本文编号：2296479
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