The aim of this work is to contribute to a better understanding of the physical aspects involved in the coefficient of lateral earth pressure at rest ( \(K_0\) ), focusing in particular on the effect of loading history on this coefficient. For this purpose, a 2D discrete element modeling of a cyclic oedometer test on a granular sample is carried out. It is shown that the evolution of \(K_0\) with loading is in good agreement with that of empirical formulas derived from experience. Analysis of the variation of certain micromechanical parameters, namely the fabric tensor, the number of contacts and the forces acting in contact with the load, has shown that for a normally consolidated granular sample, horizontal contacts are dominant, this dominance decreases with increasing degree of overconsolidation. The variation in the dominant direction of contacts is due to the differential change in the number of contacts per direction as the load varies. The orientation of the contacts may give some indication of the tendency of \(K_0\) , however, the value of \(K_0\) is more influenced by the forces acting on these contacts. The evolution of \(K_0\) according to a loop for a loading-unloading cycle in the oedometer test, is ultimately governed by intergranular friction.
Graphical Abstract
