厚煤层整层开采采场上覆关键层断裂条件判定

Determination on Fracture Condition of Key Stratum Above Full Thick Seam Mining Face

在对应用比较广泛的上覆岩层垮落公式进行分析时,发现在垮落矸石充填满采空区之前,该公式没有考虑岩层协调垮落情况,因而公式应用范围有局限。基于这一认识对厚煤层整层开采采空区顶板关键层断裂规律进行了分析,研究得出了关键层断裂判定条件。通过相似模拟试验,对公式进行理论分析,掌握其关键层及其随动层的断裂垮落特点,关键层断裂建立薄板力学模型,对其稳定性公式进行推导,得出了保持稳定的极限断裂步距,并结合实际回采条件进行计算与验证。

When analyzed the wide applied formula to the over strata falling, it was found that before the falling rejects fully filled the goaf, the formula could not consider the strata coordinately falling and thus the application scope of the formula was limited. Base on the circumstance, an analysis was conducted on the fracture law of the key layer in the roof of the goal for the thick seam full mining face. The fracture judging conditions of the key layer were obtained from the study. With the similar simulation test, a theoretical analysis was conducted on the formula and the fracture and falling features of the key layer and the follow-up layer were understood. A thin plate mechanics model of the key layer was established. After the derivation on the stability formula, the extreme fracture step distance was obtained to keep the stability. In combined with the actual mining conditions, the calculation and verification were conducted.