Modeling of settlement and induced matric suction in multiphase porous media under root water uptake effect by F.E.M

摘要

The existence of vegetation in unsaturated soil can change the moisture content of its nearby soil, especially in drought condition. This moisture content reduction produces matric suction in the soil. When the vegetation is capable of extracting significant amount of water and hence, producing large matric suction values, the study of the phenomenon becomes crucial. However, unfortunately, this phenomenon has always been neglected by geotechnical engineers. In this paper the authors have suggested a set of mathematical formulas, which sets the stage to study the effect of root water uptake in unsaturated soils. The root water uptake relationship has been written in the integral form of θ-STOCK formulation, a fully coupled formulation of unsaturated porous media proposed by Gatmiri at CERMES-ENPC. It is shown that the results of finite element simulations of the model for case studies, which are presented in this paper, are in good agreement with the results of other works and field measurements. Finally, the settlement of a strip footing near a row of trees is studied. It is shown that how vegetation water uptake can impose settlement to residential municipalities.