Behavior of circular foundation on sand layer of limited thickness subjected to eccentrically inclined load

Abstract

A numerical study on the behavior of an eccentrically inclined loaded circular foundation on a sand layer of limited thickness underlain by a rigid rough base is presented. Specific attention is given to simulating the effect of the rigid rough base, load eccentricity (e), load inclination (α) and failure mechanisms in the finite element (FE) analysis assuming axisymmetric conditions. Analyses are performed using two models, namely, (i) an elastic-perfectly plastic Mohr-Coulomb model (MCM) and (ii) an elasto-plastic hyperbolic model called the hardening soil model (HSM) using Plaxis 3D. The results of the numerical modeling indicate that the bearing capacity is modified when the rigid rough base is located at a shallow depth below the base of the foundation and the extent of the failure surface. The results of the FE analysis appear to be in good agreement with those obtained from the tests by Sethy et al. (2019) for all H/B ratios, except for H/B = 0.3. However, the results obtained by the hardening soil model are all close to the results obtained from the laboratory model tests by Sethy et al. (2019). Based on the results of the finite element (FE) analysis and the results of the laboratory model tests by Sethy et al. (2019), the modified ultimate inclined load per unit area is seen to be dependent on the H/B ratio and becomes constant beyond H/B′ ratios (where B′=B-2e) that equal about three.