Foundation design requires a great effort to estimate the capacity in order to achieve the truly successful results. Among factors affecting bearing capacity is the footing size. So, the effect of footing size on bearing capacity was previously studied by introducing footing width (B) in bearing capacity equation depending upon theoretical assumptions or laboratory bearing tests. This is the reason to neglect the effect of footing size on bearing capacity value for soil of low internal friction angle (cohesive and C-Ø soils).
In the present investigation, a series of in-situ bearing tests were carried out on cohesive soil (clayey soil) and C- Ø soil (silty soil) to study the effect of square footing size on bearing capacity. Two sites represent the two studied soils were chosen. In each site, test pits and auger boring were used to establish the stratification and engineering properties of soil. The in-situ bearing tests were performed using square steel loading plates 0.30,0.45,0.60 and 0.75 m width.