Load-Settlement Mechanism of Shallow Foundations Rested on Saturated Sand with Upward Seepage

Abstract

In this study, the ultimate bearing capacity and settlement of square and strip foundations in the presence of upward seepage were assessed using physical modeling. The experiments were conducted in two series with different loading values of excess pore-water-pressure paths. The experimental results demonstrate significant degradation of bearing capacity resulting from excess pore-pressure development; however, a remarkable amount of soil strength was observed when the excess pore-pressure ratio was unity in the free-field ground. A correction coefficient (fγ) for the bearing-capacity factor Nγ was estimated based on the results. This factor is a function of upward-seepage magnitude. Based on the experimental results, dimensionless charts are presented to predict the settlement of square and strip footings rested on saturated sand with varied amounts of excess pore-water pressure. Results show strong dependency of settlement on the bearing-capacity safety factor presumed for the foundation design.