千米深井保护层开采对下部巷道稳定性影响分析

Analysis on Protective Seam Mining Affected to Stability of the Lower Seam Roadway in 1000 Meters Deep Mine

为研究深井高应力、倾斜岩层条件下,保护层开采对下部巷道稳定性的影响,根据平煤十二矿地质情况,基于相似材料试验对保护层己14煤层开采过程中,下部己15煤层回采工作面的矿压规律进行了模拟研究。结果表明:在保护层开采前后,处于保护层采场外侧的回风巷始终受到高水平应力作用,在开挖60 cm后因采场初次来压影响,巷道下帮水平方向压应力由3.42 kPa增至50kPa,两帮变形较大;而处于保护层采场正下方的运输巷在保护层开采过程中顶板变形破坏较为严重,但保护层开采后,顶板垂直应力由最大值42 kPa降至拉应力-17 kPa,卸压效果非常明显,巷道稳定性好。

In order to study the mining in the protective seam affected to the stability of the lower seam roadway under the high stress and inclined strata in deep mine shaft, according to the geological conditions of No. 12 Mine in Pingdingshan Coal Mining Group, based on the test on the similar material, a simulation study was conducted on the mine pressure law of the gateways in the coal mining face in JJ5 seam under the protective seam Jl4 seam in mining. The results showed that before and after the mining of the protective seam, the air retuning gateway at the outside of the coal mining face in the protective seam was always affected to the horizontal high stress. After the air retuning gateway driving forward with 60 cm, due to the initial mine pressure role of the coal mining face, the stress of the left sidewall along the gateway was suddenly increased from 3.42 kPa to 50 kPa and the deformation occurred at the two sidewalls of the gateway was high. The deformation failure of the roof along the transportation gateway right under the above the mining face in the protective seam was serious dur- ing the upper protective seam in mining operation, After the mining operation completed in the upper protective seam, the vertical stress of the roof was reduced from 42 kPa to -17 kPa and the pressure releasing effect was obvious.