Softening and hardening clay soil under loading

Abstract

The processes of hardening and softening occurring in clay soil under conditions of triaxial loading are described. The reasons causing the improvement or deterioration of the soil mechanical characteristics are given, their mechanism is revealed. The physical mechanism of the effects of hardening and softening of clay soil was explained at the micro level. The main factors affecting the hardening and softening processes are called water migration in the sample, the time and quantity of deviator loading. The results of a cubic-shaped sample in triaxial compression device experimental studies with different exposure times of the deviator loading stage are presented. The tests were carried out on artificially prepared clay soil samples. Data were obtained on changes in the humidity and strength characteristics of clay soil in the characteristic zones of the sample arising during triaxial loading. In this study, the previously made spatial model of clay soil under regime loads proposed by the authors was modified taking into account the influence of water migration in the soil structure during loading and the influence of this factor on the processes of soil softening and hardening.