水射流割缝在近距离多煤层石门揭煤中的应用

发布时间：2018-09-14 07:03

【摘要】：随着矿井开采强度的增加，煤层开采中须揭穿近距离多煤层的石门逐渐增多。与单一煤层石门揭煤相比，石门揭穿多个突出危险煤层时，煤层间的距离过小会引发相邻煤层的突出危险，须制定针对所有煤层的区域防突措施，但目前常规防突技术无法有效的解决此问题。因此，开展近距离多煤层石门揭煤研究具有重要的理论价值和工程意义。本文以雷公山煤矿1085运输石门为研究对象，提出将高压水射流割缝技术应用于近距离多煤层石门揭煤的新思路，并采用理论分析与数值模拟相结合的方法确定现场割缝方案，最后在1085运输石门进行现场试验。主要研究成果如下：（1）揭示了高压水射流割缝卸压增透机理，即当煤体被切割出缝槽后，煤体发生变形，缝槽周边煤体发生损伤破坏，煤体原有裂隙扩张，煤体新的破坏裂隙形成，煤层透气性提高；较远区域煤体因煤层卸压，渗透率随着应力的降低而增大，煤层的透气性得到提高。（2）采用Comsol软件数值研究了仅5#煤层割缝、仅9#煤层割缝、5#和9#煤层同时割缝三种不同割缝工况下的卸压效应，研究结果表明，5#和9#煤层同时割缝后，5#煤层顶、底板衔接处垂向最大卸压率分别为98.6%、92.1%，9#煤层顶、底板衔接处垂向最大卸压率分别为106.5%、102.6%；而仅5#煤层割缝和仅9#煤层割缝两种工况下的割缝煤层顶、底板垂向最大卸压率能达到90%以上，而邻近未割缝煤层顶、底板处垂向最大卸压率均在20%以下。在考虑整体卸压效果的情况下，，确定5#和9#煤层同时割缝为最优工况。（3）根据优选的割缝方案对1085运输石门进行区域消突，与采用密集钻孔消突工艺的1085回风石门相比，单孔抽采瓦斯浓度提高7.8倍，单孔瓦斯流量提高13.5倍，钻孔数量减少55.9%，K1max降低40%，，石门揭煤时间缩短41%。
[Abstract]:With the increase of mining intensity, the number of stone gates in coal seam mining needs to be exposed. Compared with the single coal seam, when Shimen exposed several outburst dangerous coal seams, the small distance between the coal seams will lead to the outburst danger of the adjacent coal seams. Therefore, it is necessary to formulate regional outburst prevention measures for all coal seams. But at present, conventional anti-outburst technology can not effectively solve this problem. Therefore, it is of great theoretical value and engineering significance to carry out the research on Shimen uncovering coal in short distance multi-seam. This paper takes 1085 Shimen of Leigongshan Coal Mine as the research object, and puts forward a new idea of applying high pressure water jet cutting technology to uncovering coal in close distance multiple coal seams, and adopts the method of combining theoretical analysis and numerical simulation to determine the spot seam cutting scheme. Finally, the site test was carried out in 1085 Shimen. The main research results are as follows: (1) the mechanism of pressure relief and antireflection by high pressure water jet cutting joint is revealed, that is, when the coal body is cut out of the slot, the coal body is deformed, the surrounding coal body is damaged and destroyed, and the original crack expands. The new fracture of coal body formed, the permeability of coal seam increased, and the permeability of coal body increased with the decrease of stress in the far area because of the pressure relief of coal seam. The permeability of coal seam has been improved. (2) using Comsol software, the pressure relief effect under three different cutting conditions of only seams, 9# seams and 9# seams are studied numerically. The results show that the top of seams is cut at the same time, the maximum rate of vertical pressure relief at the joint of floor and floor is 98.6 and 92.1 respectively, and the maximum vertical pressure relief rate at the joint of floor and floor is 106.5 and 102.6, respectively. However, the maximum vertical pressure relief rate of the floor can reach more than 90% under the two working conditions of only seams with seam cutting and seam cutting only in 9# coal seam, while the maximum vertical pressure relief rate of the adjacent uncut seam roof and floor is below 20%. Considering the overall pressure relief effect, it is determined that the joint cutting at the same time is the optimal condition. (3) according to the selected seam cutting scheme, the 1085 transportation Shimen area is eliminated from outburst. Compared with the 1085 return air gate with dense borehole outburst elimination technology, the gas concentration in single hole is increased by 7.8 times, the gas discharge in single hole is increased by 13.5 times, the number of boreholes is reduced by 55.9% and K1max is reduced by 40 times, and the coal uncovering time of Shimen is shortened by 41 times.
【学位授予单位】：重庆大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TD712.62

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