Monitoring of the Shear and Compression Deformation in a Sandy Model Slope Under Artificial Rainfall

The combination of the monitoring of the surface displacement and the strain-time relation of a soil is adopted in practice to predict the time of onset of a shallow landslide. This method sometimes cannot make good prediction because the creep theory cannot treat the change of stress in the slope. Some variant should be necessary for indicating the stress state. The utility of the ratio of the increase of the compression strain to the increase of the shear strain (strain increment ratio) in the slope as the stress variant were examined in this paper based on analysis of the monitoring data of the deformation of the sandy model slope. As results, the strain increment ratio at deeper soil layer approached toward zero with the increase of the shear strain. It means the soil layer approaches the failure state. These facts show that the strain increment ratio can express the stress condition and the instability in the slope.