Development of equivalent structural models for the coupled analysis of the dynamic soil-structure interaction

The study of the dynamic soil-structure interaction for large structures may require the development of local numerical models in order to have a manageable computational demand. In this study, a novel technique is proposed in which a simplified description of the superstructure is introduced in the soil-foundation numerical model. This solution strategy was used to study the dynamic behaviour of friction dissipative foundations for suspension bridges and is being adopted to evaluate the coupled dynamic response of bridge abutments. In the proposed approach, the seismic actions on the structure derive directly from the combined effect of the propagation of seismic waves in the soil and of the interaction between the soil and the structure. In fact, this is a method to reduce the structural domain to analyze the coupled soil-structure interaction and can be used either as a direct tool to design the structural members in contact with the soil or as a means to evaluate seismic time-histories to be applied to a more refined structural model. The method allows for a direct evaluation of the interaction between the dynamic response of the structure and that of the soil deposit.