Theoretical modeling of horizontal-vertical loading of circular foundation in the offshore Niger Delta of Nigeria

Theoretical modeling on the performance of offshore circular foundation installed on clay and subjected to combined horizontal-vertical load in the Niger Delta has been attempted. Analytical methods of Skempton, Brinch Hanson, and Vesic were used to evaluate concentric vertical loads on offshore piles. Horizontal forces, H were evaluated for varying wave heights on circular piles of 1.0 to 2.0 m diameters using available meteorological and oceanographic offshore records. The results revealed that sliding failure commenced when the ratio of vertical load to footing area and undrained shear strength, V/As_u assumed negative values (i.e. at H > 0.082 As_u). The maximum mean vertical load is 6.107 As_u, and to guide against the occurrence of bearing capacity failure by sliding, V > 0.75H for cases where the ratio of footing depth to breadth ratio is lesser than one, (D/B < 1.0) and V > 0.70H when footing depth to breadth ratio is greater than one (D/B > 1.0).