The collapse behavior of a compacted soil during inundation

Abstract

The collapse behavior of a compacted, uncemented soil is studied within a theoretical context consistent with the concepts of unsaturated soil mechanics. Experimental data are presented relating the initial matric suction of a compacted soil to its volume decrease during inundation. The laboratory results indicate a unique relationship between the changes in matric suction (i.e., Δ(u a − u w ), where u a is the pore-air pressure and u w is the pore-water pressure) of the compacted soil and the resulting volume reduction during inundation. Changes in the matric suction and total volume with respect to time were modelled using the theory of transient flow through an unsaturated soil. The predicted results show reasonable agreement with the experimental observations. The comparisons between the simulated results and the experimental data indicate that the coefficient of consolidation of the soil varies linearly with matric suction during the inundation process. Key words: unsaturated soil, matric suction, collapsible soils, negative pore-water pressures.