砂土的突破压力与渗透率实验

The relationship between the pressure threshold and the permeability-porosity of thesame sample has been studied. The experimental results show that the relationship betweenthe flow rate and pressure drop in the capillary porous media is similar to that of the lam-inar flow in ordinary pipes and channels. However, the conventional hydrodynamics anddimensional analysis are not sufficient to unify the permeability-porosity relationship. Thepermeability of the narrow screened particle packed bed is not linear function of the squareof the particle or channel size. There is a pressure threshold pth occurring in a very thinlayer of wet sand when gas is forced into them, which is a capillary pressure behavior of theporous media. The threshold diameter, defining as dth=4a/pth, can unify all the experi-mental results of the permeability-porosity. The threshold diameter is neither particle sizenor channel size in the porous media. It is a non-geometrical quantity in length unit.