Numerical simulation of coal wall cutting and lump coal formation in a fully mechanized mining face

Abstract It is difficult to accurately calculate the lump coal rate in a fully mechanized mining face. Therefore, numerical simulation of wall cutting process, which revealed crack expansion, development, evolution body and corresponding formation mechanism, was performed PFC2D. Moreover, correlation established between force formation, statistical analysis method proposed determine rate. The following conclusions are drawn from results: (1) Based on soft ball model, model established. By setting roller parameters based linear bonding simulating process body, effectively simulated, accurate statistics provided. (2) Under stress, working face underwent three stages—microfracture generation, fracture penetration—to form coal, direction orthogonal pressure chain. Within certain range roller, as depth increased, number new fractures first increases then stabilizes. (3) fractured locally compressed, thereby forming compact core. destruction core causes fluctuations force. fluctuation amplitude positively related mass. (4) Because does not consider secondary damage simulated larger than actual face; this deviation mainly concentrated large with diameter greater 300 mm.