Journal of Mining & Safety Engineering ›› 2016, Vol. 33 ›› Issue (2): 191-198.

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Fracture evolution characteristics of surrounding rock during ascending mining of closer coal seam in Panyidong coal mine

  

  • Received:2015-01-15 Online:2016-03-15 Published:2016-04-22

Abstract: Based on the special engineering and geology condition of deep coal seam mining in Panyidong coal mine, the characteristics of rock break, crack evolution and subsidence deformation during the ascending mining of deep coal seams were analyzed by physical and numerical simulations in this paper. In addition, the interrelationship between the deformation curve and the layer break, crack development, stress state was further analyzed. The results show that during the mining operation of lower and upper coal seams, the rich cracks areas are mainly located in the right side of coal wall and the left side of open-off cut and above the gob. Rock layers above the gob go through an evolution course with the generating, expanding and closing of cracks. During the lower seam mining, the fractured angle in wall is smaller than that in open-off cut. During the upper seam mining, with the relative location difference of coal faces in the two coal seam, the fractured angle in wall increases firstly, and decreases af- terwards . Moreover, it has close relationship between the curve slope of roof subsidence in different area, the rock crack development condition, and the stress state.

Key words: closer coal seam, ascending mining, fracture evolution, overlying strata development, simulation analysis