Time prediction of an onset of shallow landslides based on the monitoring of the groundwater level and the surface displacement at different locations on a sandy model slope

Abstract

Selection of the location of monitoring of the deformation and the groundwater level in the slope is important for time-prediction of an onset of shallow landslides based on the monitoring. The analysis of the monitored data on the surface displacement and the groundwater level at different locations in sandy model slope under artificial rainfall was conducted in this study. The analysis revealed that surface displacement increased with the increase of the groundwater level significantly and the relation between the surface displacement and the groundwater level can be modified as hyperbolic. The surface displacement grew larger and maximum groundwater level was smaller at farther location from the toe of the model slope. Time-prediction of an onset of landslide based on the monitored data at different location on the model slope was conducted as following procedures. (1) To make the regression equation for the surface displacement - the groundwater level relation based on the monitored data at any time before the failure, (2) To make the regression equation for the time - the groundwater level relation based on the data until same time with (1), and (3) To combine the equation (2) to the equation (1) to derive the time - the surface displacement relation. (4) To derive the time - inverse of the surface displacement velocity from the equation (3). The equation for the time - the surface displacement and the equation for the time - the inverse of the surface displacement velocity could simulate the actual phenomena of the model slope well based on the monitored data at any location on the model slope.