In combination with the mining conditions of the upper protective seam in Qingdong Mine, the FLAC3D software was applied to the simulation of the floor pressure releasing law in the upper protective seam mining. The study results showed that the pressure released gas emission rate of the protected seam was 30. 0% -36. 5%. After the upper protective seam mined, the in-situ ground stress of the protected seam would be reduced from i0. 5 N i0. 8 Mpa to I. 0 ~ 1.5 Mpa. The initial pressure released location in the protected seam would be 40 - 50 m to the coal mining face. According to the study results, stereo gas control technology with roof rock roadway in coal layer, bedding drainage, a roof high level gas drainage gateway, tubing buried at the up corner, downward borehole through strata with fracturing in the air retuning gateway in the upper protective seam was set up. The engineering application showed that the pressure re- leased gas would account for 86. 8% of the total gas emission of the coal mining face, the gas emission rate of the protected seam was 30. 4% and the initial pressure releasing location of the protected seam was the location that the coal mining face advanced at 40 m.%结合青东煤矿上保护层开采条件,采用FLAC3D软件模拟了上保护层开采底板卸压规律。研究结果表明：被保护煤层卸压瓦斯涌出率为30.0%～36.5%;上保护层开采后被保护煤层原始地应力由10.5～10.8 MPa降低为1.0～1.5 MPa;被保护煤层初始卸压位置为工作面回采至40～50m。根据研究结果制定了顶板岩巷穿层钻孔、顺层预抽、顶板高抽巷、上隅角埋管及上保护层回风巷下向穿层增裂钻孔的立体瓦斯治理技术。工程应用表明,卸压瓦斯占工作面瓦斯涌出总量的86.8%,被保护煤层瓦斯涌出率为30.4%,被保护煤层初始卸压位置为工作面回采至40 m位置。
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