Time prediction of an onset of rainfall-induced landslides based on the monitoring of the groundwater level and the surface displacement

Abstract

The analysis of the monitoring data on soil-water and deformation in sandy model slope under artificial rainfall was conducted in this study. The analysis revealed that the relationship between the shear strain and the pore pressure and that between the surface displacement and the groundwater level were modified as hyperbolic as the relation between the shear strain and the stress ratio under direct shear condition of loose sand. New prediction method of the time of an　onset of rainfall-induced landslide was proposed based on the relationship between the surface displacement and the groundwater level. The procedure is as follows. 1) To make the equation for the prediction of the relationship between the surface displacement and the groundwater level based on the regression analysis at any time before the failure, 2) To make the equation for the prediction of the relationship between the time and the groundwater level based on the regression analysis, and 3) To derive the equation for the prediction of the relationship between the time and the surface displacement by the combination of the former equation to the latter equation. The equation of the relationship between the time and the surface displacement could simulate the actual deformation of the model slope well. It suggests the utility of the method for the time prediction of an onset of the rainfall-induced landslides.