Porosity, permeability, and moduli are the properties most fundamental to assessing skeletal deformations and water flow rates in porous materials. For saturated materials, these properties are similar for both “soft” and “stiff” material skeletons, but greatly simplified models can be used when the skeleton is relatively soft. The effective stress is a key parameter for both soft and stiff materials when saturation is complete, but is much less powerful for partially saturated materials.

Ideally, the needed properties of porous materials should be determined from an integrated program of laboratory testing, field testing, and solution of the inverse problem using a...