Hunan Vocational Institute of Technology
School of Resource Environment & Safety Engineering, Hunan University of Science & Technology
Production Technology Management Center, China Coal Pingshuo Group Co. , Ltd.

为解决近距离煤层工作面回采过程中,相邻煤层瓦斯易从导通的采动裂隙带大量涌入工作面,带来瓦斯超限等安全问题,以山西小回沟煤矿近距离煤层开采为研究对象,采用相似模拟试验和现场试验研究了该矿03#、2#煤层在重复采动影响下围岩应力—裂隙演化特征规律,圈定了采场上覆岩层裂隙带范围,确定了抽采钻孔合理位置,提高了瓦斯抽采效果。试验结果表明:03#煤层回采时,工作面推进至33、50m时,离层最大发育高度分别为4、14m,随工作面推进,离层最大发育高度为28m;02#煤层在03#煤层裂隙带范围内,裂隙形成了瓦斯运移通道;工作面推进33m时,开切眼后方覆岩支承压力增高,压力集中系数约为1.6,开切眼与工作面之间出现卸压区,工作面前方出现应力增高区,压力集中系数约为1.6,随着推进距离的增加,支承压力集中系数增加至2.74;2#煤层回采时,采空区两端出现明显的竖向裂隙,与03#煤层原有裂隙相贯通,并扩大贯穿至模型顶部,覆岩支承压力集中系数由2.55下降至1.95。现场试验中,将2201工作面高位钻孔终孔控制在采空区上方30~35m裂隙发育区,回风巷瓦斯浓度由0.78%降至0.35%,取得了良好的瓦斯治理效果。

In order to solve the problem that during the process of coal winning in contiguous seams, the adjacent coal seamface is advanced to 33 m, the abutment pressure of overburden increases behind the open - off cut, and the pressure concentration coefficient is about 1. 6. There is a stress-relaxed area between the open-off cut and the working face, and a stress-concentrated area in front of the working face. The pressure concentration coefficient is about 1. 6. With the increase of the advancing distance, the abutment pressure concentration coefficient increases to 2. 74. When No. 2 coal seam is coal winning, significant vertical cracks appear at both ends of the goaf, which are connected with the original cracks of No. 03 coal seam. It expand and run through the top of the model, and the abutment pressure concentration coefficient of overburden decreases from 2. 55 to 1. 95. In the field test, the final hole of high-level borehole in 2201 working face was controlled in the fracture development area of 30 m to 35 m above the goaf, and the gas concentration in the return airway was reduced from 0. 78% to 0. 35%, which achieved good gas control effect.

湖南省自然科学基金科教联合项目(2022JJ60058)

唐建华,吴吉南,余伟健. 近距离煤层瓦斯抽采覆岩应力—裂隙场演化规律研究[J]. 矿业安全与环保,2023,50(3):48-55.

TANG Jianhua,WU Jinan,YU Weijian. Study on evolution law of stress-fissure field of overburden in contiguous seams extraction[J]. Mining Safety & Environmental Protection,2023,50(3):48-55.