Interesting idea, though outside my experience, and probably that of anyone else here.
I wouldn't expect to find an off-the-shelf program that would do that for you, but you might be able to get some help from university researchers that do earthquake modeling, possibly U of British Columbia. They have a constitutive model called, oh so cleverly, UBCsand, that MAY be a two-phase model, as opposed to a nonlinear solid. (It was developed primarily by Peter Byrne, now retired but probably hanging around still doing research.) The two-phase dynamic modeling I can recall seeing is primarily oriented toward softening and loss of shearing resistance as loose sands are liquefied by shaking. For dynamic response behavior, the water is usually "attached" to the soil skeleton, where it adds mass and high bulk density without adding shear stiffness or shear strength. (For slow compression, allowing time for pore water to seep out, the bulk modulus is orders of magnitude less than for very rapid loading where the water doesn't have time to seep out. Poisson's ratio for rapid loading of sat'd soil is pretty close to 0.5, whereas it can be as low as 0.35 or so for slow loading, allowing drainage.) Would that work for your problem, or do you actually need to model it as two phases? Doesn't seem there would be a whole lot of movement of fluid within and among the cells of the porous solid, even for a basso profundo.
Let us know if anything works out for you.
Regards,
DRG
