大倾角煤层顶板垮落充填量化特征及覆岩分区破断分析

Quantitative features of roof caving and filling in steep coal seam and analysis on the sub-regional fracturing of overburden

为探究大倾角煤层开采直接顶垮落在采空区下部量化充填特征、覆岩破断特征和工作面长度的影响规律,分析了直接顶破碎岩块在采空区倾斜方向的滑移规律,并推导出采空区下部区域充填接顶长度L的计算公式;基于此,分析了基本顶破断失稳量化特征,推导出基本顶沿走向和倾向上的破断失稳公式,并结合工程实例运用UDEC数值模拟验证了理论推导的合理性。结果表明:大倾角煤层开采在直接顶垮落自行充填的作用下,基本顶沿倾斜方向分为稳定区、易失稳区和悬顶区,并且各区段长度与工作面长度呈正相关;基本顶发生破断的位置处于破碎岩块充填体的上方,并且会在充填体的作用下沿倾斜方向上保持一定长度(L-x1)的稳定结构。该研究可以为大倾角工作面合理长度的布置提供借鉴。

In order to explore the quantitative filling law of the immediate roof caving in the lower part of goaf, overburden fracture features and influence law of working face length.We analyzed the sliding law of the broken rock block in the goaf in the inclination direction, and deduced the calculation formula of the filling length(L) in lower part of goaf;on this basis, the quantitative features of the main roof fracture and instability are analyzed, and the main roof fracture and instability formulas on the direction and inclination of the main roof are derived, and the UDEC numerical simulation is used in conjunction with engineering examples to verify the rationality of the theoretical derivation.The results show that under the action of the immediate roof caving and self-filling in the mining of steep coal seams, the main roof is divided into a stable area, an unstable area and a suspended roof area along the dip, and the length of each section is positively correlated with the length of the working face.The fracturing occurs above the broken rock filling body, and will maintain a stable structure of a certain length(L-x1) along the dip under the action of the filling body.This research can provide a reference for the reasonable length arrangement of steeply inclined working face.