Coefficient of earth pressure at rest for normal, consolidated soils

In this study consecutive consolidated isotropically drained triaxial tests for the coefficient of earth pressure at rest (K0) were carried out to investigate its rules of evolution as well as its strength characteristics for normal, consolidated saturated silt under high pressure. The tests results indicate that: 1) for normal, consolidated saturated silt, K0 values increase as the consolidation stress increases at high pressure levels, while the nonlinear characteristics of K0 are inconspicuous compared to cohesive soils; 2) the Jaky and Roscoe equations, used to calculate K0, are only suitable for certain soils, but cannot represent these values for normal, consolidated saturated silt due to the variation in bilinear strength at high pressure; and 3) there are close relations between the nonlinear characteristics of K0 and the void ratio, measured in the tests. Both share the same functional form while under pressure. Based on our experimental results, we developed an empirical linear model to interpret the rules of nonlinear variation for the coefficient of earth pressure at rest.