下伏煤层瓦斯压力消散数值模拟

平煤五矿己15煤层为低瓦斯煤层,下伏己16-17煤层为高瓦斯煤层,相对层间距比例1.0-4。己16-17煤层煤厚3.5m,为主采煤层。为降低己16-17煤层的瓦斯压力,实现安全高效生产,该矿以已15煤层为保护层,采用上保护层开采技术改变具有突出危险的煤层瓦斯赋存状态,降低被保护层的瓦斯压力。基于多孔介质流体流动理论,利用有限元数值模拟技术,模拟平顶山五矿超近上保护层的开挖过程,分析被保护煤层的瓦斯流动过程和煤层瓦斯压力的变化规律,论证保护层开采技术可以改变高突、高瓦斯煤层瓦斯赋存状态的可行性。

Numerical analysis of coal-gas pressure relief

The D15 coal seam in the Fifth coal mine in the Pingdingshan Coal Mining Group was the seam in which the gas volume is low, and the D16-17 coal seam was threatened by the potential of coal-gas outburst. The thickness of the D16-17 coal seam is 3.5 m averagely, which was the key coal seam. The D15 coal seam was treated as the protective strata, which could relief the gas pressure of the D16-17 coal seam and make sure the production more efficiently and safely. The coal-gas existing condition was ameliorated in the coal seams prone to coal-gas outburst, adopting the mining method of protective strata. The gas volume and the gas pressure are reduced synchronously in the protected coal seam. The analysis was based on the theory of the porous media flow with the finite element method. The gas flow process and the change mechanism of the coal-gas pressure were analyzed in the process of mining the protective strata. The key problem was to prove the practicability that the mining method of the protective strata could change the coal and gas condition in the seam prone to coal-gas outburst.