Effect of Non-linear Soil-Structure Interaction on Seismic Response of Slender Structures

Some Structures tend to be very massive and may have to be located on relatively soft soil. In such cases, the soil adjacent to the structure, which behaves in nonlinear fashion, affects the response of the structure to the dynamic loading. To take into account this non-linear soil-tructure interaction effect on the behaviour of structures a hybrid method is described in this paper that combines the boundary finite-element method and finite-element method to model the soil and structure parts of soil-structure system, respectively. The consistent infinitesimal finite-element cell method is employed to model the nonlinear (near-field) zone of the soil supporting the structure as a series of bounded media. The material properties of the bounded media will be selected so that they are compatible with the average effective strains over the whole bounded medium during the excitation. The linear zone of soil away from the foundation, the far-field, is modeled as an unbounded medium using the consistent infinitesimal finite-element cell modeling technique for unbounded mediums. The proposed method is used to model the dynamic response of a practical tower supported on a homogenous stratum and excited by an earthquake