Assessment of the Behavior of Conical Shell Footings on Elastic Foundation

In this research the interaction of the conical shell footing and the supporting soil taking into account the contact surface characteristics is investigated. The two components of the interacting system are modelled using Abaqus/CAE 6.13 finite element analysis programme. The general characteristics for the contact between shell footing and the supporting soil including, separation, kinetic frictional slip of finite amplitude, arbitrary rotation of the surfaces and pressure-overclosure are accounted for in the finite element model. Moreover, geometric nonlinearity to account for large deformations and displacements due to slip is included. Conical shell footing prototype is analyzed using different finite element discretization approaches for the contact surfaces including tie constraint and tangential friction interaction models. A Comparison study with previous researches reveal that the tangential friction interaction model yield more realistic values for shell response. Generally, traditional Winkler foundation model overestimate maximum shell settlement by about 50 % and meridional membrane stresses by about 100 %, whereas shell hoop stresses were underestimated by about 70 %, especially at the shell edges. The interaction assessment study reveal that conical shells with wide apex angle are susceptible to increased settlement and hoop stresses, whereas conical shells supported on weak (soft) soils are susceptible to large hoop membrane stress at the edges which give rise for edge stiffeners (ring beam).