近浅埋煤层开采顶板垮落步距分析

Analysis of Roof Falling Pace in Mining Shallow Buried Coal Seam

以榆阳煤矿2302工作面的开采实践为工程背景,利用"板"和"梁"两种力学模型对近浅埋煤层开采基本顶初次来压步距进行了分析和计算,结合基本顶实际垮落步距确定出适合近浅埋地质条件下的力学模型,并计算了"板"力学模型在不同边界条件下初次来压步距。为了解决基本顶初次来压步距过大的问题,根据采场处于不同边界条件下初次来压步距的特点,提出了采用深孔预裂爆破和区段煤柱宽度缩小的方法,使采场处于"两边固支两边简支"的受力状态,以减小初次来压步距,保证初采初放期间工作面顶板安全。

Based on mining practice of 2302 Mining Face of Yuyang Colliery, this paper applied two mechanics models of ＂board＂ and ＂beam＂ to analyzing and calculating first roof weighting pace of basic roof in shallow buried coal seam. Actual failing pace of basic roof was considered to select mechanics model which was fit for shallow buried coal seam. With ＂board＂ model, this paper calculated dif- ferent first roof weighting paces under different boundary conditions. Then, it put forward a method of pre-split blasting and decreasing width of district sublevel coal pillar to make mining field under stress of ＂fixed at two sides＂ and ＂simply supported at other sides＂. With this method, the first weighting pace may be reduced, which ensure face safety during first roof weighting.