Effect of footing roughness on ultimate bearing capacity of rigid strip footing on sandy soil slope

This study investigates the ultimate bearing capacity of a rigid strip footing on a sandy slope using the Rigid Plastic Finite Element Method (RPFEM). To accurately represent a wide range of frictional conditions at the footing roughness, a new interface element was introduced, capable of accommodating both perfectly rough and perfectly smooth conditions. A new constitutive equation is introduced to model these interface elements, which had a significant influence on the failure mode of the strip footing. Moreover, the study focuses on assessing critical parameters, including the internal friction angle of the sandy ground, as well as slope geometry parameters (slope angle b, edge distance L, and slope height H). The RPFEM results illustrate that increasing the edge distance positively influences the bearing capacity, while a higher slope angle exerts a negative effect. Notably, variations in slope height produce consistent outcomes, regardless of the frictional conditions.