Nonlinear estimation model of minimum void ratio for sand–silt mixtures

Abstract

Previous experimental studies on sand–silt mixtures have shown that silty fines significantly affect the soil fabric and resulting mechanical behavior. Some bilinear models have been proposed to capture minimum and maximum void ratios. In this study, previously reported data from 37 soil mixtures including coastal sands with 338 individual specimens for which the minimum void ratios are available were studied. The results helped form the basis to develop a nonlinear model capable of estimating the shape of the minimum void ratio curve of the sand–silt mixtures. The equations of minimum void ratios were derived for soil mixtures in coarse and fine grain dominant regions. The results show that the predicted values of minimum void ratios by quadratic polynomial equations agree well with the measured data; the root mean square error is 0.03. The proposed model only requires one data point from the experimental test to predict the minimum void ratio for any soil mixture with various fine contents.