Soil Stabilization by Ambient Pore Pressure and Geomembrane Containment

Substantial atmospheric and pore water pressures exist in soil deposits. These pressures may be used to exert additional confining stresses with the aid of relatively impervious barriers. Any reduction in pore pressure within the impervious boundaries of an isolated soil domain will result in an equal increase in confinement. Confinement that directly increases effective stress will in turn increase shear stiffness and strength of the soil. In situ applications are becoming increasingly feasible in view of the recent advances in construction and installation of geomembrane systems. In this study, the concept of increasing confinement by action of ambient pore pressure is discussed. The effectiveness of this approach when applied to dry and saturated cohesionless soil is evaluated using a series of centrifuge model tests. In these experiments, a major increase of soil resistance to deformations is observed. In the saturated soil models, the potential for liquefaction induced deformations is eliminated. Practical applications and the applicability of retrofit efforts including the required geomembrane characteristics are discussed. Currently, field tests are needed to assess full-scale implementation challenges.