Energy approach to the analysis of partially-saturated flow

When fluid passes into or out of an aquifer, work is done at the boundaries which is partly used to change the internal energy of the system and partly to overcome resistance to flow. For a saturated medium, the change in internal energy is further partitioned into two terms - the strain energy stored in the elastic soil matrix and the strain energy stored in the pore water due to compression. A technique is described in this paper which …