Experimental Study on the Coefficient of Earth Pressure at Rest for Sand

Abstract

The coefficient of earth pressure at rest K0 is a state soil variable correlated with relative density Dr. As previously conducted K0 tests could not guarantee zero lateral deformation in the sand specimens, significant errors occurred in the test results. In this paper, a centrifugal model test method is used to study the K0 of sand with varying densities. The sand specimens with varying relative densities are prepared by sand pluviation, and a 50 g-ton centrifugal force is applied. Subsequently, the relationship of K0 and Dr with different densities is analyzed. The test results show that for the same type of sand, the value of K0 gradually increased with Dr. Based on the meso-evolution characteristics of sand particle recombination, various relationships between K0, the displacement deflection angle, and the friction offset angle between particles are analyzed. Furthermore, the relationship between particle volume fraction and K0 is derived, the assumption of increasing the coefficient K0 with the increase in Dr is verified, and the effect of Dr of sand on the force transfer behavior of the internal particle fabric is briefly discussed. The research results could significantly improve the current earth pressure theories.