Evaluation of Soil Contribution to Seismic Response of Soil-Structure Systems Using Recorded Data During Small-scale earthquakes

This paper investigates the importance of super-structure modeling in estimating soil’s contribution to the seismic response of soil-structure systems. For this purpose, soil-structure systems with different lateral resisting systems are studied and the values for the main parameters of the system, including parameters determining the soil-structure-interaction (SSI) and the contribution of flexural and shear deformation to the total response of the system are determined. To this end, a one-bay frame with flexural-shear behavior is utilized to model the super-structure in the soil-structure system. In this research, different soil-structure systems are studied using artificial and real acceleration floor responses. The results from investigating different soil-structure systems showed that the proposed method to identify the system can estimate the main parameters of the soil-structure system with acceptable accuracy. Moreover, the results showed that two different systems with different lateral resisting systems and the amount of soil’s contribution can be identified with almost the same floor acceleration responses. For an instant, a moment-frame system located on soft soil with relatively high soil-structure-interaction may have the same floor acceleration responses as a shear-wall located on firm soil with less soil contribution. This observation shows the importance of using more realistic modeling for the super-structure in soil-structure systems to achieve more reliable estimates of soil’s contribution to the system’s response.