Design Charts for Bearing Capacity Factor of Conical Footings in Clay

Bearing capacity analyses are crucial for the design of offshore foundations. While extensive studies have focused on the vertical bearing capacity of flat circular foundations in clays, the behavior of a significant number of foundations that are in a conical shape remains under exploration. Moreover, limited research has been conducted on buried conical footings under uniaxial loadings. To address these gaps, this study presents findings from a series of finite-element limit analyses on the undrained bearing capacity of conical footings in clay under vertical and moment loadings. A total of 5,184 running cases were conducted to determine the vertical and moment bearing capacity factors, considering critical factors such as conical angle, embedment depth, footing roughness, and soil strength heterogeneity index. The accuracy of the analyses was benchmarked against published solutions, and the obtained bearing capacity factors are presented as design charts. Algebraic expressions for the vertical and moment bearing capacity factors have been derived for spudcan-shaped footings and flat footings. These results contribute to improving current design practices for footings in clay and are particularly beneficial for offshore foundation analysis in cohesive soils, considering the aforementioned critical factors.