Numerical investigation for failure load and contact stress beneath RC square footing resting on cohesionless soil

The contact pressure distribution below, reinforced concrete footing, does not solely depend on the type of soil, but also on the change of the footing stiffness after cracking. This paper presents a numerical simulation and validation for full-scale square reinforced concrete footing rested on sand soil using a nonlinear finite element program “ABAQUS 6.14” to investigate the effect of concrete damage plasticity on contact stress distribution beneath the footing. It was found that, as long as the foundation stiffness decreases during the loading cycle for the footing, the percentage of the contact stresses at the footing edges to the contact stresses under the column center are reduced. A parametric study is conducted on square concrete footings with various reinforcement ratios resting on sand soil to investigate the effect of increasing reinforcement ratio on the failure load, and the shape of the contact stress below the footing before and after cracking. The results determine the impact of increasing the steel reinforcement ratio from 0.15 % to 0.30 % on the footing performance, and the corresponding increases in the ratio between central to edge contact stress. The findings further indicate that contact stress distribution below square footing was not consistent with the theoretical assumption.