Rapid increase rate of using flat slabs and flat foundations is noticed in different reinforced concrete projects. These concrete elements have many features in their concrete casting and reinforcement placement, but on the other side, the non-ductile punching shear failure around the supporting columns is the main issue. Many experimental and statistical studies have been focused on assessing the punching shear capacity of centric flat plate elements. Due to the size effect and fracture mechanics, the behavior of a thick flat foundation is not typical of the behavior of the thin elements, as the shear crack inclination angles with thick elements are steeper than those in thin flat plates. The difference in behavior is increased with eccentric loadings. Construction imperfections and/or limited foundation space are the main reasons for these eccentricities. This puts limitations on using some previously developed punching shear formulas when dealing with thick footing elements. This numerical study investigates the behavior of both centric and eccentric loaded flat thick footings without and with shear reinforcement. This study showed a good prediction for the punching shear strength of footings with different eccentricity levels compared to the reference case studies. The results demonstrate that higher eccentric levels significantly reduce the strength of footings without shear reinforcement. However, the footing deformation capacity was improved. Parametric studies utilizing the validated developed numerical models have been conducted to assess the efficiency of two nonconventional shear reinforcements; U and S-shaped. Both options significantly increased the footing punching shear strength and improved the deformation capacity. In addition, the S-shaped reinforcing option showed its efficiency in limiting the strength reduction to 8% compared to 17% for footing without shear reinforcement under load eccentricity less than 1/9 of the footing length. Moreover, the arrangement of the S-shaped reinforcement can govern the behavior of the footings under different load conditions. The results of providing two identical amounts of S-shaped reinforcement showed that one closely spaced row is more efficient under centric loading while two rows are more suitable under eccentric loading.