Study And Application Of Key Strata Theory In Shallow Seam Of Shendong Mining Area

The key strata theroy in shallow seam mining of Shendong mining area was further studied in this paper by theoretical analysis, numerical simulation, physical simulation, field test and engineering detection. The main contents include the parts as follows: structure classification and breaking characteristics of key strata of overlying strata in shallow seam mining of Shendong mining area, distinguish method and correlation parameters of key strata in shallow seam of Shendong mining area, the influence laws of the key strata movement on surface subsidence in shallow seam mining, the influence laws of the key strata movement on water flowing fractured zone development and roof water inrush in shallow seam mining of Shendong mining area, the mechanism and prevention and cure of abnormal water inrush in roof at NO.4 panel of Bulianta Mine.The key strata structuer is classified to two classes and four species for the first time in the paper. The formation conditions of complex singleness key strata structure in shallow seam mining was put forward and distinguish method was also given. The breaking characteristics and mechanical mechanism of complex singleness key strata structure were analyzed and the same to up coal seam postharvest singleness key strata structure. According to the observation of interior rock movement drilling, some key parameters such as the load transfer coefficient and rock breaking angle were determined when the key strata is distinguished in the shallow seam mining of Shendong mining area. The control action of key strata movement to surface subsidence dynamic process in shallow seam mining was revealed in the paper. After analyzing the influences of the subsidence observation interval periodic on subsidence dynamic curve configuration and the maximal subsidence velocity, the characteristics and basic parameters of surface subsidence in shallow seam mining was summarized and the influences of the key strata movement on water flowing fractured zone development in shallow seam mining was also given. After analyzing the mechanism of abnormal water inrush in roof at NO.4 panel of Bulianta Mine, the prevention and cure measures were brought forward and achieved obvious effect and good economic benefit.