Numerical Investigation of the Effect of Soil-Structure Interaction on the Seismic Behavior of Steel Structures with Shear Walls

Abstract: Generally, in the design of structures, the soil under the structures is considered rigid, and the effect of soil-structure interaction is ignored. However, the soil under the structure is not rigid in reality, and the presence of soil under the structure will cause changes in the dynamic characteristics of the structure and consequently change its response. The type of soil and the flexibility of the foundation are among the factors that can affect the analysis results to some extent. Therefore, depending on the type and depth of the soil of the construction site, building structures will have a different response to the bedrock. On the other hand, the effects of soil-structure interaction are due to inertial interaction and kinematic interaction. Of course, methods are proposed in some international seismic codes to analyze soil-structure interaction. However, due to the complexities of kinematic interaction, they often only consider the effects of inertial interaction. In this article, using Abaqus software, a three-dimensional model of a 5, 10, and 15-story steel structure with a core shear wall and side shear wall structural system is compared and investigated, taking into account various soil types under the structure and comparing it with a structure with a rigid foundation under earthquakes. The results of this research show that maximum shear forces at the base of a building are concentrated at the top surface of any rafts supported by hard shear walls, and they decrease upward. At the top of the raft, the bending moment reaches its maximum of 240%. In the shear-walls scenarios, bending moments and shear forces at the walls' base are significant regardless of the supporting soil media due to the connection with the raft foundation slab. Keywords: Soil-Structure Interaction, Period, Seismic Behavior, shear force, story drift