突出煤层保护层开采效果考察研究

Investigation and study on mining effect of protective layer in outburst coal seam

磴槽煤矿属于煤与瓦斯突出危险的矿井,开采保护层是有效预防突出的技术之一,通过对保护层开采防突效果进行考察,研究了保护层开采前后蹬槽煤矿22041工作面煤层变形量、透气性系数、瓦斯抽采量。现场实验结果表明,被保护层22041工作面在下保护层22521工作面开采后,受到采动作用的影响而发生一定程度的变形。经过充分卸压,煤层最大膨胀变形可达4.98 cm,相对膨胀变形15.09‰。被保护层透气性系数由保护层开采之前的0.06~0.2174 m^(2)/(MPa^(2)·d)增大为保护层开采后的3.4547~15.1884 m^(2)/(MPa^(2)·d),透气系数增大了57.5~69.8倍。被保护层瓦斯抽采总量达153206 m3,其中,被保护层卸压瓦斯抽采量达121033 m3。对被保护层在保护层开采前后的煤层变形量、透气性系数、瓦斯抽采量进行综合评价说明,22521煤层开采对22041煤层起到了区域消突的保护作用。

Dengcao Coal Mine belongs to coal and gas outburst dangerous mine,and mining protective layer is one of the effective technologies to prevent outburst.Through investigating the outburst prevention effect of protective layer mining,this paper studies the coal seam deformation,permeability coefficient and gas extraction volume of 22041 coal seam working face of Dengcao Coal Mine before and after protective layer mining.The field experiment results show that after the 22041 working face of the protected layer is mined in the 22521 working face of the lower protective layer,it will be deformed to a certain extent under the influence of the mining action.After full pressure relief,the maximum expansion deformation of coal seam can reach 4.98 cm,and the relative expansion deformation is 15.09‰.The permeability coefficient of the protected layer increases from 0.06~0.2174 m^(2)/(MPa^(2)·d)before the protection layer mining to 3.4547~15.1884 m^(2)/(MPa^(2)·d)after the protection layer mining,and the permeability coefficient increases by 57.5~69.8 times.The total amount of gas extraction from the protected layer is 153206 m~3,of which the amount of pressure relief gas extraction from the protected layer is 121033 m~3.The comprehensive evaluation of the coal seam deformation,permeability coefficient and gas extraction of the protected layer before and after the mining of the protective layer shows that the mining of 22521 working face plays a role in regional outburst elimination for 22041 working face.