Correction to the gas phase pressure term in the continuum model for partially saturated granular media presented by Pietruszczak and co‐workers

Abstract Pietruszczak and coworkers (Internat. J. Numer. Anal. Methods Geomech. 1994; 18(2):93–105; Comput. Geotech. 1991; 12( ):55–71) have presented a continuum‐based model for predicting the dynamic mechanical response of partially saturated granular media with viscous interstitial liquids. In their model they assume that the gas phase is distributed uniformly throughout the medium as discrete spherical air bubbles occupying the voids between the particles. However, their derivation of the air pressure inside these gas bubbles is inconsistent with their stated assumptions. In addition the resultant dependence of gas pressure on liquid saturation lies outside of the plausible range of possible values for discrete air bubbles. This results in an over‐prediction of the average bulk modulus of the void phase. Corrected equations are presented. Copyright © 2003 John Wiley & Sons, Ltd.