| The rapid and accurate calibration of meso-parameters is of utmost importance for the correct simulation of rock mechanical properties in PFC. Thus far, the calibration methods for flat-joint model (FJM) meso-parameters have not considered the bonding ratio, ?b, which significantly influences both Poisson’s ratio and compression-tension ratio, and the coefficient of variation of bonding strength, Rsd, which significantly influences rock strength and difficulty of crack formation. Crack initiation strength, σci, is a macro-parameter that is not often considered; however, it is an important index to judge the damage range of surrounding rock. Therefore, ?b, Rsd, and σci were included in parameter calibration study. Orthogonal numerical tests were conducted to study the correlation between the eight meso-parameters of the FJM and the six macro-parameters of the rock. The fitted relationships between each of the macro-parameters and main meso-parameters were determined; furthermore, analysis of the trend relationships between the macro- and meso-parameters was conducted. Based on the above, a FJM meso-parameters calibration method was proposed, and the calibration method was used to calibrate the meso-parameters of the gneiss granite, whose macro-parameters have already been experimentally determined. The calibrated numerical model was used to perform a series of numerical experiments, and the calibration method is verified to be feasible because the results of the numerical experiments are close to that of the physical experiments. |
