Abstract

The Darcy's experimental law is valid in the case of linear laminar steady flows through saturated porous media. Although this law is still widely used, it is not valid in the case of laminar unsteady or cyclic flows due, for instance, to the action of short waves within soils and earth structures, which can affect their behaviour and durability. The present paper presents a new extension of Darcy's law particularly suitable to these unsteady flows. The model is first derived from the Navier-Stokes equations combined with a capillary-type model. For validation of the model, an experimental device simulating flows due to short waves within soils was developed. 95 unsteady tests conducted on five, different sands have confirmed the validity of the law identified. The results of the tests show the effects of acceleration, which generates an increase of the interstitial pressure within the soils.