Time effect and prediction of broken rock bulking coefficient on the base of particle discrete element method

• Published in: 矿业科学技术学报（英文版） 2021, Vol.31 (4), p.643-651
• Main Authors: Fanfei Meng, Hai Pu, Takashi Sasaoka, Hideki Shimada, Sifei Liu, Tumelo K.M Dintwe, Ziheng Sha
• Format: Article
• Language: English
• ISSN: 2095-2686
• DOI: 10.3969/j.issn.2095-2686.2021.04.010

Bulking characteristics of gangue are of great significance for the stability of goafs in mining overburden in the caving zones. In this paper, a particle discrete element method with clusters to represent gangue was adopted to explore the bulking coefficient time effect of the broken rock in the caving zone under three-dimensional triaxial compression condition. The phenomena of stress corrosion, deformation, and failure of rock blocks were simulated in the numerical model. Meanwhile, a new criterion of rock fragments damage was put forward. It was found that the broken rock has obvious viscoelastic proper-ties. A new equation based on the Burgers creep model was proposed to predict the bulking coefficient of broken rock. A deformation characteristic parameter of the prediction equation was analyzed, which can be set as a fixed value in the mid-and long-term prediction of the bulking coefficient. There are quadratic function relationships between the deformation characteristic parameter value and Talbot gradation index, axial pressure and confining pressure.