关键词: 浅埋煤层, 厚硬顶板, 特厚煤层, 综放开采, 矿压显现规律, 强动载, 区域压裂

Abstract: Aiming at the problems of strong mine pressure behavior and frequent occurrence of strong dynamic load in fully mechanized caving face of shallow buried thick hard roof and extra thick coal seam in caojiatan coal mine of Yushen mining area, the law of strong mine pressure behavior in working face is studied and summarized at first.The results show that:the average step distance of periodic pressure on the working face is 18.4m, the average continuous distance of pressure is 11.5m, and the average dynamic load coefficient is 1.45,the pressure mainly affects 35#~125# support. The periodic weighting of working face has the characteristics of strong dynamic load, long duration, obvious regionality and periodic strong mine pressure. The working face has a large period weighting at an average interval of 135m. In case of large-scale periodic weighting on the working face, there is generally strong continuous pressure, accompanied by large-scale and long-term opening of the support safety valve(the opening ratio of safety valve is more than 50%) and continuous and rapid downward decline of the support movable column(the maximum reduction of the support exceeds 2.0m). In order to reduce the threat of strong mine pressure caused by the hard roof, the underground directional horizontal long borehole regional fracturing technology is used to pre crack the hard roof of the working face. After the implementation of regional fracturing, the intensity of mine pressure in the working face has been significantly weakened, and the phenomenon of strong mine pressure behavior with rapid roof subsidence has not occurred again. The regional fracturing has achieved good application results, which can be used as a reference for the treatment of strong mine pressure in shallow buried thick hard roof face in Yushen mining area.