An Investigation on the Effective Damping Ratio Considering Soil-Structure Interaction(I)

An Investigation on the Effective Damping Ratio Considering Soil-Structure Interaction(I)

To incorporate the effects of Soil-Structure Interaction(SSI) into the structural design, the most important issue is to quantify the effects of SSI for a soil-structure system. For design purpose, it is well recognized that the natural frequency and associated damping ratio are the key parameters for structural analysis. The natural frequency and associated damping ratio of the Equivalent Fixed-Base(EFB) model constructed can be calculated through explicit equations, and can represent the dynamic characteristics of the original soil-structure system. In this study, preliminary comparisons between the recommended provisions for Seismic Regulations considering SSI effect of FEMA450 and the EFB model of a SDOF structure are advanced and discussed.