Centrifuge model tests for deformation mechanism of soil slope during rainfall

A series of centrifuge model tests for deformation mechanism of soil slopes under rainfall were conducted using the rainfall simulation system in centrifuge. The models were loaded to 50g; and then the rainfall was generated. The displacements of slopes during the rainfall were measured by the image-analysis-based system; and the suctions of typical positions were measured by the tensiometers T5. The results show that the displacements of slopes increased as the rainfall proceeded and the deformation area centralized on the face of the slope and gradually enlarged as the water penetrated into the soil. The strain changing of soil elements has a close relationship with the suction variations. The strain of a typical soil element started to increase quickly just as the water content increased of the element. The strain of the soil element increased as the rainfall proceeded. The strain-rainfall curve has two inflexions; and based on which two fronts are defined. The slope is divided into three parts by the two fronts; and the deformation process of the slope can be described by the fronts' movement.