5.Law of overburden movement and stress field evolution in fully-mechanized mining face of shallow-buried coal seams

Abstract:

To explore the overburden movement of working face roof and the evolution law of stress field in shallow-buried single coal seam mining, taking a certain mine in Shendong as the background, the method combining physical simulation and numerical simulation was adopted to reveal the overburden movement and working face strata pressure behavior law in single coal seam mining. The research shows that with the advance of the working face, the caving height of overburden and the fracture development height roughly present linear growth, the growth rates are 0.6 m/m and 1 m/m respectively. During the initial weighting of the working face, the peak value of the advance abutment pressure is greater than that during each periodic weighting. Specifically, the peak advance abutment pressure during the initial weighting is approximately 2.5 times the in-situ stress(1.92 MPa), while the peak advance abutment pressure during periodic weighting is about 1.95 times the in-situ stress. In addition, during the initial weighting, the advance abutment pressure of the working face is farther from the coal wall, but its influence range in front of the working face is the largest, approximately 44 m.

Keywords: shallow-buried coal seam working face;overburden movement;stress concentration;strata pressure behavior