EQUIVALENT LINEAR PARAMETERS FOR NONLINEAR SOIL-STRUCTURE SYSTEMS WITH EMBEDDED FOUNDATION

In this study, the concept of equivalent linearization, in which the actual nonlinear structure is replaced by an equivalent linear single-degree-of-freedom (SDOF) system, is extended to soilstructure systems with embedded foundation. This is done by searching over a two-dimensional equivalent period-equivalent damping space for the best pair which can predict the earthquake response of the inelastic soil-structure system with sufficient accuracy. An extensive parametricstudy is done for a wide range of soil-structure systems subjected to a suite of earthquake ground motions. The results indicate that SSI may strongly affect the equivalent parameters, especially for the case of stiff structures located on relatively soft soil. Moreover, it is shown that the equivalent parameters proposed in this study provide more reliable approximation to the system response than the current seismic provisions do.

Keywords:

Soil-Structure Interaction , Equivalent Linearization , Equivalent Period , Equivalent Damping , Reliability