Calibration method of mesoscopic parameter in sandy cobble soil triaxial test based on PFC3D

This paper presents a rapid and effective calibration method of mesoscopic parameters of a three-dimensional particle flow code (PFC3D) model for sandy cobble soil. The method is based on a series of numerical tests and takes into account the significant influence of mesoscopic parameters on macroscopic parameters. First, numerical simulations are conducted, with five implementation steps. Then, the multi-factor analysis of variance method is used to analyze the experimental results, the mesoscopic parameters with significant influence on the macroscopic response are singled out, and their linear relations to macroscopic responses are estimated by multiple linear regression. Finally, the parameter calibration problem is transformed into a multi-objective function optimization problem. Numerical simulation results are in good agreement with laboratory results both qualitatively and quantitatively. The results of this study can provide a basis for the calibration of microscopic parameters for the investigation of sandy cobble soil mechanical behavior.