Analysis on characteristics of damaged field of surrounding rock and face of FMTC

Abstract

Numerical simulation-FLAC3D and equivalent material simulation were carried out to analyze the damaged patterns and lows, distribution of plastic width of face, and surrounding rock of FMTC during the advance of work face with different thick coal seams based on engineering geology and exploitation technology of 1151(3) fully mechanized top-coal caving (FMTC) face in Xieqiao Colliery. The results show that there is damage, and the destruction characteristics of surrounding rock and coal mass are different obviously in asymmetric exploitation layout. The damaged zone in surrounding rock and the coal of the return airway is larger than that of the intake airway. Moreover, the retained coal pillars are all damaged by tension and shear fracture, and plastic zone in coal mass in the dip direction ahead of Face is nonuniform. There are large damage zones in roof and floor strata, surrounding rock, and coal of return and intake airways near work face. The damaged zone in the upper part of Face is larger than that in middle and lower parts. The fruits of this paper are of guiding significance for engineering practices, such as support design and choice, roadway supporting and maintaining, rock pressure control of FMTC face, etc.