浅埋深首采工作面采空区“三带”分布规律

Distribution of “Three Zones” in Goaf of the First Mining Face with Shallow Buried Depth

以青龙寺煤矿首采工作面5-20101工作面为背景,采用理论研究、数值模拟和现场实测对其采空区"三带"分布规律进行了研究。研究结果表明:在工作面开采后,根据采空区内压力分布情况,将采空区垮落带划分为自然堆积区、破碎堆积区和重新压实区,这三区与采空区自燃"三带"存在基本对应关系;工作面回风侧氧浓度出现较大波动,但总体呈下降趋势,主要是由于受工作面采动影响,出现大量采动裂隙,这些裂隙与地表联通,造成工作面采空区漏风,受地表大气压影响,采空区内氧浓度发生变化。

Taking the first mining face of 5-20101 working face in Qinglongsi Coal Mine as the background, the theoretical research, numerical simulation and field measurement are used to study the distribution of ＂three zones＂of the mined-out area,the results show that： after the working face mining, according to the distribution of pressure in the goaf, the collapse zone of goaf is divided into natural accumulation zone, accumulation and crushing zone and compaction zone, and there is a basic correspondence between these three zones and th e＂three zones＂of spontaneous combustion in goaf; the concentration of oxygen on the return air side of working face fluctuates greatly, but overall is on the decline, and a large number of mining-induced fractures occur mainly due to the influence of mining on the working face. These cracks are connected with the surface, which causes air leakage in the goaf of the working face. Under the influence of the surface atmospheric pressure, the oxygen concentration changes in the goaf.