Water Migration Influence on Changes of Physical and Mechanical Characteristics a Clay Soil Under Triaxial Loading

Abstract

AbstractTo study the issue of moisture migration and density changes in the sample during the test, the authors conducted experimental studies on the changes in the clay soils physical and mechanical characteristics under triaxial compression conditions in various devices: cubic and cylindrical. Experimental studies conducted have made it possible to establish that the duration of the loading stage significantly affects the volume of the fluid being moved. It was established that regardless of the sample regime loading and the test equipment type, a complex stress state is formed in the sample, which contributes to the formation of different density and humidity zones. The dimensions of these zones, the soil density and humidity, its mechanical characteristics within the specified zones are not constant and change during loading. In the soil sample loading process, two mutually compensating processes occur. The first softening process is due to the formation of microcracks and macrocracks. Secondly, this is the process of hardening due to the restoration of water-colloidal bonds between the clay soil particles and the “healing” of defects. The hardening and softening of clay soil mechanism is established.KeywordsTriaxial loadingClay soilWater migrationSpecific cohesionHardeningDesign model for dilating soil