Effect of Static Stiffness of Soil on Internal Force Distribution of Building Structures Subjected to Earthquake Loads

Abstract The soil structure interaction model is developed by substructure modeling method. For the purpose of comparative study, the SSI depth is varied by 0m, 1m, 3m, and 5m. To consider this case the foundation soil of firm soil, soil class-A and the soft soil, soil class-C is used to comparative study. By considering rigid foundation, the soil can be replaced by a set of equivalent springs and dashpots in the inertial interaction analysis. The soil structure interaction can be modeled by using equivalent static spring modeling method and static stiffness of spring can be calculated by using the supporting soil properties. To calculate elastic static stiffness of soil the most well-known G. Gazetas equation is used. The static stiffness calculated shows that for the increased depth of soil structure interaction there is increased static stiffness. So, the calculated static stiffness is used as elastic spring constant and it is assigned on the footing column base of building structure which modeled by SAP200 software. Time history analysis is conducted by applying earthquake load on the structure by using SAP200 V 14.