Soil-structure interaction in a base and mid-story seismically isolated building

The main goal of this study is to analyze the performance of seismic isolation systems by implementing isolation to the base and inter-story of the buildings together, in order to reduce the earthquake impact in multi-story buildings. In addition the soil-structure interaction for these cases are taken into consideration. An example building model was composed to observe the effect of base isolation and mid-story isolation numerically. Analyses were performed by using SAP2000 software. A five story building was used as an example structure. Investigations were carried out for six different combinations that are: fixed base buildings, buildings with soil-structure interaction, buildings incorporating single base isolation system with and without consideration of soil-structure interaction, buildings with base and mid story isolation system with and without consideration of soil-structure interaction. Two different earthquake motions were selected for time-history analysis. The results obtained from time-history analysis were discussed comparatively, for all the base-isolation cases including and excluding soil-structure interaction. It has been concluded that the seismic isolation application of the base and mid-story improves the seismic performance of the building. In addition, it has been observed that the soil-structure interaction affects the building seismic performances according to the reference ground type.