Effect of rising water table in an unsaturated slope

Recently, climatic changes have caused more extreme weather conditions such as heavy rain falls and droughts. Therefore, climatic changes are expected to produce increased variations in infiltration characteristics and positions of water table in slopes. A physical slope model has been developed to study the effects of climatic changes in an unsaturated slope. The effect of rising water table in an unsaturated slope was investigated experimentally in the physical slope model. In addition, finite element analyses were carried out to simulate infiltration in slopes under steady-state and transient conditions. A comparison between the results of laboratory model measurements and numerical analyses shows good agreement despite the complex unsaturated soil conditions. Both, experimental data and numerical analyses demonstrate a delayed response in pore-water pressure in the unsaturated zone due to the rising of water table. A conceptual framework is presented to describe the physically possible lower and upper limits of pore-water pressures in a slope resulting from the rise in water table. (C) 2010 Elsevier B.V. All rights reserved.