Bearing response of skirted foundation on nonhomogeneous soil

Circular skirted offshore foundations on nonhomogeneous soil have been stud ied numerically, analytically, and physically, with the offshore sediment s imulated as a cohesive soil with strength increasing linearly with depth. I n the numerical analysis, the h-adaptive FEM is adopted to provide an optim al mesh, in which a strain-superconvergent patch recovery error estimator a nd mesh refinement with subdivision concept are used. This paper presents t wo main studies of circular skirted foundations on nonhomogeneous soil, con sisting of a bearing-capacity study and a large penetration study. The bear ing capacity of the foundations is studied with the degree of nonhomogeneit y (kD/s(uo)) of soil up to 30, different skirt roughness and skirt depth up to five times the foundation diameter (i.e., D-f/D = 5), using an h-adapti ve FEM and extended upper-bound method. The bearing-capacity values and soi l flow mechanisms are discussed. In the foundation large penetration study, circular skirted foundations penetrating into normally consolidated and ov erconsolidated soils are tested physically in the centrifuge and analyzed n umerically using the h-adaptive remeshing and interpolation technique with small strain method for soil large deformation analysis. The load-displacem ent responses from centrifuge test data and finite-element results are comp ared.