Physical modeling of desiccated slopes in fine soil using a geotechnical centrifuge

Desiccation in soils leads to a loss of water content, increasing soil suction, which in turn, leads to higher shear strength. Drying paths in soils are produced by water uptake by plants or by evaporation due to extreme seasonal changes. This study presents the results of geotechnical centrifuge tests on the effect of water content on deformations and on the failure mechanism of a slope in fine soil. The failure mechanism and the resulting displacements obtained in the experiments were determined using image analysis using the GeoPIV_RG software. The results show a significant effect of soil suction on the failure mechanism. For saturated soils, the slope suffers an abrupt failure mechanism due to shear strength, while for partially saturated soils, this mechanism is modified and the magnitude of deformations diminishes as soil suction increases. Meanwhile, the size of the traction crack decreases as suction levels increase due to the increase in tensile strength produced by the loss of water content.