厚表土层大采高工作面矿压规律研究

Analysis on Mine Pressure Law of High Cutting Coal Mining Face Under Thick Alluvium

为研究厚表土层对大采高工作面矿压规律的影响,以亭南煤矿二盘区205大采高工作面为工程背景,采用理论分析、现场实测的方法进行了研究。分析得出:厚表土层对大采高工作面矿压影响具有一定的滞后性。表土层中含有黏土层易"成拱自稳"而在一定距离内对工作面围岩控制影响不大,随着工作面的推进,C19主关键层将弯曲下沉,表土层结构的稳定性受到破坏,主关键层断裂后表土层载荷通过其下伏岩层传递至工作面;工作面推进至198.5m以后来压期间矿压显现明显,主要表现为支架支护阻力及动载系数增大、来压步距减小、来压强度周期性增大;非周期来压期间工作面支架平均工作阻力在后一阶段大于前一阶段,支架工作阻力沿工作面倾向分布呈"中间大、两头小"的形态,机尾一侧阻力较大。

To study the mine pressure law under thick alluvium, based on the engineering background of high cutting mining face of the No. 2 panel in Tingnan Coal Mine, theoretical calculation and field measurement were conducted. The results show that, impact of thick alluvium on the mine pressure is hysteretic, as the clay stratum tends to form arch to self - stabilize, which has limited influence on the mining face surrounding rock control within a certain distance ; With the advancement of mining face, C19 key strata curves and subsides, and the alluvium structure destabilizes, transmitting the load of alluvium to working face through the rock stratum; And as the mining face advances to further than 198.5m, the working resistance of support and dynamic load factor increases, and the weighting step decreases, showing a more obvious periodicity ; During non - periodic weighting, working resistance of support at the later stage was higher than the previous stage, working resistance at middle of the coal mining face was higher than that at both two ends, and the working resistance near coal cutter tail was larger.