远距离煤层开采工作面布置方式卸压增透效应

Effect of pressure released and permeability improved induced by working face arrangement under long distance coal seam mining

为了研究远距离煤层上行开采工作面布置方式对卸压增透效果的影响,根据潘二煤矿11223工作面地质条件,通过FLAC^(3D)数值模拟软件研究远距离煤层卸压开采应力场、位移场、裂隙场分布特征,并以卸压系数为判据,确定工作面卸压增透范围。研究表明:西二段工作面采用垂直布置方式,下方11223工作面开采会引起上覆11224工作面位移场、应力场发生明显变化,11224工作面中部卸压系数达90. 37%,卸压效果良好;东一段11224工作面采用风巷外错90 m、机巷内错90 m的方式布置,导致11224工作面下部卸压系数88. 97%,卸压效果较好,而在工作面上部卸压效果不明显。通过对比,可以确定远距离煤层上行开采时,工作面采用垂直布置可获得更好的卸压增透效果。

In order to study the effect of pressure released and permeability improved induced by working face arrangement under long distance coal seam upward mining,according to the geological conditions of the 11223 working face in Panji No.2 Coal Mine,the FLAC3D numerical simulation software was used to study the distribution character of stress field,displacement field and crack field after the pressure relived mining,and make sure the pressure released and permeability improved area depend on stress relief coefficient under different mining condition. The results indicate that: the working faces were vertically arrangement in the west second segment,the mining of lower 11223 working face can induce remarkable change in stress field,displacement field of upper 11224 working face,the stress relief coefficient is 90. 37% in the middle part of 11224 working face,which can make a good stress relief effect. However,in the east first segment,the 11224 working face used the 90 m outward stagger mode in ventilation entry and 90 m inner stagger mode in conveyor entry,the stress relief coefficient is 88. 97% in the lower part of 11224 working face,this can make a good stress relief effect,while the stress relief is very feeble in the upper part. To sum up,it can make a better effect of pressure released and permeability improved when working faces apply vertically arrangement under long distance coal seam upward mining.