Les écoulements en milieu poreux et l'hypothèse de Dupuit

Flow in porous media and Dupuit's hypothesis

Ingénieur à la SO.GR.E.A.H., Grenoble.

Résumé

Dupuit's hypothesis is frequently adopted in studying flows in a natural porous media and this simplification is usually justified in view of the size of the water tables studied, where the depth is slight compared to the area. It is first shown that this hypothesis can under certain conditions provide a means of calculating the horizontal flow rates, especially as far as wells and other structures are concerned, when the wather-bearing formation is composed of ground which is stratified or homogeneous on a large scale. The usual hypothesis of homogeneous conditions and isotropy is therefore often superfluous. The author continues by showing, in the case of media with horizontal strata or aquifers of fresh over salt water, that the horizontal flows can be calculated with strict accuracy, ignoring Dupuit's hypothesis when the boundary conditions permit. Practically speaking, therefore, for both these cases the discharge/recession relationships for structures can be defined without the need to carry out the extremely complex operation of determining all the flow characteristics.