Study on the Calibration of Meso-Parameters of Granular Material Based on DEM Simulating the BE Test

A method for calibrating meso-parameters in numerical simulations of granular media by the discrete element method (DEM) was studied in this work. Firstly, the resonant column (RC) test was carried out to calibrate the test results of the bender element (BE) test, in order to eliminate the drawback of the near field effect affecting the subjectivity in determining the shear-wave travel time. Secondly, the BE test was simulated by DEM, which was used as the calibration criterion for the meso-parameters in the simulations. Under the condition that the simulated material was the same as the BE test, the meso-parameters were adjusted to minimize the errors of the received shear-wave travel time between the DEM simulation and the BE test. It was found that the contact model in particles and the friction coefficient were the crucial factors affecting the consistency between the DEM simulation and the BE test. In addition, local damping and modest increases in confining pressure can effectively reduce errors in DEM simulations. The received signal in the effective simulation segment was affected by the boundary reflection, but the calibration criterion was not affected significantly.