ABSTRACT
Following the work of Khalili et al. (2008), the differential equations governing fully coupled flow and deformation in unsaturated porous media may be expressed as
v w a[ ( ) ( ) ]p∇ u ψ p δδ 1 0F+− = (1)
div k k
div a p a p
μ ψ
( )p ρ∇⎛⎝⎜ ⎞ ⎠⎟
= + 11 12 (2)
div k k
div a p a p
μ ψ
( )p ρ
( )
∇⎛⎝⎜ ⎞ ⎠⎟
= + −22 21 (3)
with
a c a a a c nw wn a a11 12 22 21= + = +, (4)
where D is the drained stiffness matrix of the soil, u is the displacement vector of the solid skeleton, pa is the pore air pressure and pw is the pore water pressure. k is the intrinsic permeability of the soil, krw is the relative permeability with respect to the water phase, kra is the relative permeability with
1 INTRODUCTION
Numerical modelling of unsaturated soils is a subject of great interest in geotechnical engineering practice. Indeed, the description of the hydromechanical behavior of unsaturated soils in a multiphase setting, and the correct identification of the model parameters have been a key area of research in modern geomechanics.
