大倾角大采高工作面顶板结构研究

Study on Roof Structure of Large Mining High Angle Mining Working Face

为得到大倾角煤层倾斜方向顶板结构及失稳特点,以河北某矿大倾角大采高的704工作面为背景,建立了工作面顶板结构模型,结合FLAC3D、UDEC数值模拟结果得到结构失稳特点:顶板拱结构在工作面的中上部的剪切力最小,最容易发生滑落失稳来压,顶板的破坏是从工作面中上部开始并逐渐向下发展的。现场支架工作阻力实测数据表明:来压期间工作面中上部应力变化大于两端;来压时上部、中部、下部支架阻力值分别增加22.4%、21.4%、18.3%。

To understand the roof structure and instability characteristics of its dipping direction, take704 large mining high angle mining working face in Hebei province as a background. By means of numerical simulation results from FLAC3 Dand UDEC, it turns out that structure instability has following characteristics: roof arch-structure owns the smallest shearing force on the middle and upper parts of working face, which leads to the easiest happening of sliding instability weighing; damages of roof happens gradually from middle and upper parts to the ends of working face. Testing data of working resistance from on-site support shows that: variation of stresses on the middle and upper parts is bigger than that of both ends when the working face is in the period of pressure; its upper parts is bigger than that of middle and ending parts, with an increase of 22.4%, 21.4% and 18.3% respectively.