Modélisation numérique de l'écoulement à travers et sur une digue

Details

Supervisors

Soares Frazao, Sandra ; Rattez, Hadrien

Faculty

Ecole polytechnique de Louvain

Degree label

Master [120] : ingénieur civil des constructions, à finalité spécialisée

Abstract

enThis work deals with the numerical modeling of flows on and through earthen dikes. A flow model coupling those two types of flows is realized. The work is divided into three parts. The first part deals in depth with the Richards equation describing non-permanent flows in unsaturated soils. This equation was first solved in a one-dimensional case with an implicit solution scheme. Then, a formulation for a two-dimensional and unstructured mesh using the finite volume method was derived. This formulation is simple, new and has many advantages. The developed method is mass conservative, provides consistent results which have been, for some, validated from other works. Moreover, the implementation is robust and efficient. Numerous test cases have been carried out as well as studies on the critical parameters of the simulation of the Richards problem. A module allowing to take into account the hysteretic behavior of soils subjected to wetting-drying effects has also been developed. The second part deals with surface flows described by the Saint-Venant equations. A model is developed to solve them using a finite volume resolution scheme. This model is validated by comparison with various classical test cases. The third part of this work allowed to realize the coupling of the two phenomena. From a spatial point of view, this one is purely coupled whereas from a temporal point of view it is decoupled. The infiltration of water in the soil has been taken into account in the Saint-Venant system by means of a source term allowing the coupling to be conservative in terms of mass. Different test cases have been satisfactorily tested, including cases simulating overflow.