关键词: 突出煤岩层, 瓦斯抽排孔群, 损伤评估, 井壁

Abstract: Aiming to ensure the security of deep vertical shaft through the coal and rock seams which are disturbed by array gas-discharging holes, the disturbing mechanism is analyzed, and a damage evaluation model is established based on the damage mechanics theory. Then, the stability of disturbance coal and rock seams, mechanical response of rock excavation and shaft lining placement are simulated by numerical method specific to a km deep vertical shaft in Haizi coal mine. Based on the analysis result, support scheme of deep vertical shaft through the coal and rock seams disturbed by array gas-discharging holes is optimized. Results show that, to evaluate the damage of coal and rock seams disturbed by array gas-discharging holes, the erosion action of water in drill hole, pressure-relief and ar- ray holes effect of coal and rock seams should be considered at the same time, as the integrating of the three effect causes a larger damage of coal and mudstone stratum than the siltstone stratum. Disturbed coal and mudstone stratum is apt to be unstable in a great range. In order to ensure the stability of surrounding rock and support, firstly, before the vertical shaft pass through the relevant strata, gas-discharging holes are used in pre-grouting to reinforce the surrounding rock; secondly, during the excavate and pouring process of shaft lining, some strengthened initial support is constructed in time, and the tensile properties of shaft lining concrete is improved; thirdly, after the shaft lining pass through the disturbed strata, the surrounding rock is reinforced by backfill grouting in time.

Key words: gas outburst coal seam and strata, array gas-discharging holes, damage evaluation, shaft lining