Study of the linear and nonlinear packing model based on mixing of quartz sand

Packing density is an important engineering behavior aspect of the soil. The models in this experiment were compared using laboratory test packing data and published spherical particle packing data. The results show that the deviation between measured and predicted values of the nonlinear model is lower than that of the linear model. The root mean square error (RMSE) of the nonlinear packing model ranged from 0.01 to 0.06, considerably less than that of the linear packing model. The value of the wall effect for each of the models is similar, but variation of the loosening effect is large based on a comparison of the empirical parameter of the linear packing density model (LPDM), compressible packing model (CPM), Kwan model (KM) and modified Kwan model (MKM). When the characteristic diameter ratio is larger than 02, the wedging effect parameter becomes constant. (C) 2020 Elsevier B.V. All rights reserved.