Abstract: The acquisition of a precise coefficient of earth pressure at rest (K0) is very important for earth pressure calculation, and the study of nonlinear characteristics of K0 has great practical significance. Nevertheless, the research on nonlinearity of K0 for coarse-grained soils has long been neglected. To fill the gap, this study presents a detailed analysis of the nonlinearity characteristics of K0 for coarse-grained soils. Based on the incremental stress-strain relation of Duncan-Chang model, we establish the mathematical formula of K0, and the sensitivity analysis of the K0 formula is presented. The proposed method is applied to predict the K0 of coarse-grained soil experimental data reported by others and by DEM method. Comparison results show that the calculated K0-value is very close to the experimental K0-value, particularly for coarse-grained soils. Furthermore, we compared the K0-value from Jaky formula and that from the proposed method, and discussed the influence of initial stress condition on K0 for coarse-grained soils. The research findings of this study are helpful for the understanding of nonlinearity and the precision of K0 in coarse-grained soils, and may provide reference for related earth pressure calculations.

Key words: coefficient of earth pressure at rest (K0), nonlinearity, earth pressure, coarse-grained soil, Duncan-Chang model