A Simplified Strategy to Simulate the Nonlinear Behavior of Clay for Seismic SSI Analysis

Proper modeling of the dynamic behavior of the soil significantly affects the accuracy of the soil–structure interaction analysis results. Using nonlinear constitutive models has the highest accuracy in modeling soil behavior under earthquake loading. However, it is not functional for practical engineering purposes because of the high cost and complexity. The equivalent linear method also has many limitations, such as filtering out the high-frequency components of the input excitation, underestimating surface ground motion over long periods, and considerable error in high soil strain levels. The current study aims to present an accurate, simple, and low-cost method to model the nonlinear behavior of clays. This method does not meet the limitations of the traditional methods and fully considers the effect of the influential parameters. The novel central composite design technique was adopted to evaluate the effect of influential variables on the nonlinear behavior of clay and formulate the proposed method. The introduced method is applicable to various building structures, power planets, etc. Numerical analyses performed on the proposed method and nonlinear modeling confirm the accuracy, efficiency, and generality of the proposed method.