寺家庄矿回采工作面预抽钻孔抽采半径考察研究

Investigation study on drainage radius of pre-extraction boreholes at mining work face of Sijiazhuang Mine

寺家庄矿通过在回采工作面制定多组不同间距的抽采钻孔试验方案,考察了预抽钻孔的抽采半径,得出在钻孔有效抽采时间内,当抽采时间相同时,钻孔间距越小,预抽率越高;预抽率随时间延长有整体增加的趋势,但增加的速度逐渐减小;对于一定间距的钻孔而言,当抽采时间达到某一值时,抽采率的变化与抽采时间的延长无关,即存在一个合理预抽时间的概念;根据允许预抽时间的长短,由相关公式可得出合适的抽采半径,为科学布置预抽钻孔提供依据,保障矿井采、掘、抽平衡。

Experimental schemes with different distances between drainage boreholes at mining work face in Sijiazhuang Mine inspected the drainage radius of pre-extraction boreholes and figured out that when the effective drainage time was the same, the smaller borehole distance indicated higher pre-extraction rate. The pre-extraction rate increased with time, but the rate of increase decreased gradually. For boreholes with certain distance, there was no correlation between pre-extraction rate and drainage time when drainage time reached a certain value, which means there exists the concept of reasonable pre extraction time. According to the length of allowable pre-extraction time and related formula, suitable drainage radius could be calculated and provided guidance for scientific layout of pre-extraction boreholes, guaranteeing the balance between mining, driving and drainage.