刀柱采空区下极近距离煤层联合综放开采矿压显现规律

发布时间：2018-11-18 10:38

【摘要】：近距离煤层开采不同于单一煤层开采,其矿压显现规律存着显著的差异。上部煤层选择的开采方式对于近距离煤层下部煤层的开采造成的影响也不尽相同,且随着煤层层间距的减小,这种影响程度会随之增大。刀柱采空区下极近距离煤层开采同时具备了煤层间距非常小和上部煤层遗留煤柱对于下部煤层的开采作用十分明显的特点。由于上部煤层经刀柱法开采后遗留了大量的煤柱,受到煤柱的应力集中的影响,下部煤层的顶板特征、覆岩结构、支架和围岩的相互关系、开采时的矿压显现特征等方面全部体现出较大差异性。王封煤矿现在主要开采的9号煤层,距离其上部8号煤层间距仅仅为0.75m,且8号煤层采用刀柱法开采后遗留了大量的煤柱,9号煤层采用“采9放8”联层综放进行开采,属于上述讨论的范畴。本文基于王封煤矿的实际作为研究蓝本,以实地调研、实验室物理力学参数测定得到的信息为出发点,综合运用理论分析结合相似模拟实验研究9号煤层开采时采场的矿压显现规律,最后通过在井下展开的矿压观测进一步验证和丰富了矿压显现特征的内涵。主要研究内容如下:1、通过理论分析了遗留煤柱的受载状态特征和煤柱自身的强度极限,同时还对煤柱塑性区分布特征进行了讨论,从而对煤柱的稳定性展开了综合分析。2、探究了上部煤层遗留煤柱向底板传递应力的分布规律。3、构建了刀柱采空区下极近距离煤层采场覆岩结构模型,基于弹性力学对固支梁及悬臂梁结构模型进行理论计算确定了顶板初次及周期来压步距。4、根据刀柱采空区下极近距离煤层开采覆岩运动规律,将“载荷层一老顶一煤柱一直接顶一支架”这一整体结构分为两个通过煤柱联系的子结构,并求得支架合理的支护阻力。5、基于王封煤矿9101工作面设计了相似模拟实验,对采场上覆岩层的垮落规律以及开采应力变化规律进行了分析。6、通过在现场进行的矿压观测进一步对刀柱采空区下极近距离煤层联层综放开采矿压规律展开了探究,与理论计算得出的结论基本吻合。
[Abstract]:Close coal seam mining is different from single coal seam mining. The influence of the mining mode chosen by the upper coal seam on the coal seam in the lower part of the near coal seam is different, and with the decrease of the coal layer spacing, the influence degree will increase. At the same time, the mining of extremely close distance coal seam in the cutting pillar goaf has the characteristics of very small coal seam spacing and the obvious effect of the coal pillar left by the upper coal seam on the mining of the lower coal seam. Because a large number of coal pillars have been left over after the upper coal seam is mined by the cutter pillar method, it is affected by the stress concentration of the coal pillar, the roof characteristics of the lower coal seam, the overburden structure, the relationship between the support and the surrounding rock, In mining, the characteristics of rock pressure show great difference. The distance between the No. 9 coal seam and the No. 8 coal seam in Wangfeng Coal Mine is only 0.75m, and a large number of coal pillars have been left after the No. 8 coal seam was mined by the knife pillar method, and the No. 9 coal seam is mined by "mining 9 caving 8" fully mechanized caving. Falling within the scope of the above discussion. Based on the actual situation of Wangfeng Coal Mine, this paper takes the information obtained from field investigation and physical and mechanical parameters measurement in laboratory as the starting point. Combined with theoretical analysis and similar simulation experiment, the characteristics of mine pressure behavior in coal seam No. 9 are studied. Finally, the characteristics of mine pressure behavior are further verified and enriched through underground pressure observation. The main research contents are as follows: 1. The characteristics of load state and strength limit of coal pillar are analyzed theoretically, and the distribution characteristics of plastic zone of coal pillar are also discussed. Therefore, the stability of coal pillar is analyzed synthetically. 2, the distribution law of stress transfer from coal pillar left over in upper coal seam to the floor is explored. 3. The overburden structure model of coal seam under the cutting pillar goaf is constructed. Based on elastic mechanics, the theoretical calculation of the structural model of clamped beam and cantilever beam is carried out to determine the initial and periodic pressure step distance of roof. 4. The integral structure of "load layer, main roof, coal pillar, direct roof and support" is divided into two substructures connected by coal pillars, and the reasonable support resistance is obtained. 5. Based on the similar simulation experiment designed at 9101 face of Wangfeng Coal Mine, The law of caving and the variation of mining stress of overburden strata in mining stope are analyzed. 6. Through the observation of mine pressure in the field, the law of fully mechanized top-coal caving in the coal seam of extremely close distance under goaf is further explored. It is in good agreement with the conclusion obtained by theoretical calculation.
【学位授予单位】：太原理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TD325.3

【相似文献】