Breakage mechanism and pore evolution characteristics of gangue materials under compression

Filling of gangue formed in coal mining is an effective means to realize green mining in coal mine. The key of gangue filling mining is to accurately understand the breaking mechanism and pore evolution of gangue under load. Therefore, in this paper, firstly, the yield criterion of granular materials based on radius of curvature and contact stress is built, which concluded that the change of grain size during the process of gangue compression is the main factor affecting the crushing characteristics of gangue. Secondly, the numerical simulation method which can simulate the loading of gangue is put forward, and realize the re-crushing of gangue under compression and the influence of particle shape on the compression and crushing of gangue. Finally, the calculation method of breaking rate based on single particle is given, and the influence of the location of gangue particle on the breaking rate of rock sample is analyzed.