Stress-Settlement Response of Circular Foundation on Granular Layer Overlaying Compressible Normally Consolidated Soil

Abstract

Bearing capacity of foundations is typically estimated by assuming the soil strata to be homogeneous and rigid plastic. However, for footingson compressible strata is influencednot only by the strength parameters but also by the settlement of the soils beneath the foundation. Stress-settlementbehavior of footings on soft ground is inherently nonlinear due to compressibility nature of the soil. Naturally sedimented soils undergo variations in undrained shear strength with depth. Compressibility and heterogeneity ofnormally consolidated (NC) soil influence the bearing stress as a function of settlement. The current study considers circularfooting resting on granular bed overlaying compressible normally consolidated soil (GNC). The numerical study quantifies the effects of NC soil’s heterogeneity and compressibility,as well as granular layer thickness on stress-settlement responses of footings on GNC soils.Results of the present study depict that bearing stress increases with rigidity and heterogeneity in NC soil as well as the with the thickness ofgranular layer.The increments in stress with granular layer thickness and NC soil heterogeneity increase with footing settlement, whereas they decrease with the rigidity of NC soil. The influence of granular layer thickness on bearing stress is more significant for given footing settlement when compared to that due to heterogeneity and rigidity of NC soil.