Study on the Broking Mechanism of Roof Stratum of Coal Seam

In this paper, the numerical simulation of the process of the overlying roof stratum braking cased by excavating the shallow-lying coal seam is carried out by the use of the Strata Failure Process Analysis programme (SFPA2D) which is developed by Northeastern University self, the elastic modulus and shear stress distribution patterns, the displacement curves of ground surface subsidence and the stress distribution in the roof stratum of coal seam for step-by-step excavation are gotten out. Through analyses of the results obtained from the numerical simulation, the caving, fracturing and bending zones in overlying stratum failing, and the basic laws of coal seam pressure distribution and ground surface deformation during excavating shallow-lying coal seam have being revealed. The values of ground surface subsidence obtained from the example numerical simulation approach to the measured ones extremely. 