Laboratory experiments on moisture content variation and landslides caused by transient rainfall

Rain induced landslide is increasingly becoming major natural disaster. Although pore-water rise in the soil domain is taken as the cause of the landslide, it is yet not clearly known the response of pore-water pressure in different complexities of the soil domain. Multiple layers of soil with different hydraulic properties is one of the common complexities found in the field. We have tried to find out the mechanisms of moisture content variation and landslides in single and two layered slopes. The results showed that the upper layer which has higher hydraulic conductivity experiences slide first in case of two layered slope while slide of whole depth occurred in the single layered slope. A numerical model was also prepared to simulate the infiltration and landslide due to rainfall. The results as timing of landslide and moisture movement pattern from experiment and numerical simulation are quite close. The results encourage further research towards making landslide predication model.