Near-Field's Dynamic Properties for Dynamic Soil- Structure Interaction Analysis

Direct and substructure methods are two main approaches for modeling dynamic soilstructure interaction problem. In this research the problem of soil-structure interaction analysis with the direct method is studied. The direct method consists of modeling the superstructure and underlying soil domain. Using reduced shear modulus and an increased damping ratio resulted from an equivalent linear free-field analysis is a traditional method for simulating soil medium behavior. However, this method is not accurate enough in the vicinity of foundation where the soil experiences large strains and the behavior is highly nonlinear. This research proposes modified modulus degradation and damping ratios for using in the near-field zone in order to obtain more accurate results. As the properties of the region near the foundation is dependent on both superstructure and soil properties, near-field modulus degradation and damping ratios have been presented as functions of dimensionless parameters controlling nonlinear behavior in the near-field. Semi-analytical models have been proposed and the ability of this method was evaluated. The results of verification example show the accuracy of this approach.

کلیدواژه ها:

soil-structure interaction ، equivalent linear method ، near-field ، modulus degradation