Analysis of Main Controlling Factors of Overburden Failure in Coal Mining Under Thick Coal Seam Geological Conditions

Abstract

According to the theory of elastic mechanics half plane, the mechanical model of roof overburden failure is established. Based on the numerical simulation software FLAC3D, the failure process of roof overburden in 1308 working face is numerically simulated according to the orthogonal experimental design scheme. Matrix analysis and variance analysis are used to analyze and calculate the simulation results to determine the sensitivity of the main control factors to the failure height of overlying rock of mining roof. The results show that: (1) with the increase of mining depth and the advancing distance of working face, the subsidence of roof overburden increases. (2) The order of influence of main controlling factors on roof overburden failure height is: mining depth > working face length > internal friction angle > mining thickness > coal seam dip angle > cohesion > tensile strength. (3) Variance analysis showed that the mining depth height was significant, the working face length and internal friction angle were significant, and the significance of working face length was slightly greater than that of internal friction angle, and other factors were not significant.