Experimental study on the deformation and failure of a cut slope under rainfall

On June 11, 2016, a landslide occurred in Miaoling village, Jiujiang city, Jiangxi Province, China, following continuous rainfall. An engineering geological profile indicated that the landslide consisted of a stiff crust of residual Quaternary deposits overlying a water-sensitive gravelly clay layer with a soft-plastic consistency. A geotechnical field investigation and physical models of rainfall-induced landslides were carried out in situ and in the laboratory and included the use of a new sensors to develop a geotechnical model of the cut slope. During the rainfall process in the physical simulation experiments, automatic rainfall, three-dimensional scanning, and multiparameter monitoring were conducted to analyze the resulting landslides. The results showed that the increase in moisture and the generation of pore water pressure led to changes in soil pressure and the development of plastic deformation. An analysis performed after rainfall using a strain-softening behavior model showed the initiation and propagation of plastic zones, as well as the development of landslide cracks close to the observed ones. Therefore, it was proposed that the Miaoling–Jiujiang landslide could be explained by a progressive failure mechanism.