Bearing capacity of shallow foundations in saturated and unsaturated sands from SPT–CPT correlations

Abstract

The in situ bearing capacity of sandy soils is determined or estimated using plate load tests (PLTs), cone penetration tests (CPTs), or standard penetration tests (SPTs). The contribution of matric suction toward the bearing capacity of unsaturated sands is, however, not estimated from these tests. In this paper, SPTs and PLTs were conducted in situ on sandy soil in Ottawa, Canada under saturated and unsaturated conditions to demonstrate the contribution of matric suction on the bearing capacity results. In addition, relationships are proposed to estimate the bearing capacity of sands under both saturated and unsaturated conditions from the SPTs results. Comparisons are provided between the measured and estimated bearing capacity values for three different sands from the literature using the proposed relationships. The results of the study suggest that the proposed relationships can be used in the estimation of the bearing capacity of both saturated and unsaturated sands.