Hadi Kenarangi - Graduate Student, Earthquake Engineering, Civil Engineering Department, Sharif University of Technology, Tehran, Iran
Fayaz R. Rofooe - Professor, Civil Engineering Department, Sharif University of Technology, Tehran, Iran

This paper investigates the performance of Tuned Mass Dampers (TMD) in reducing the nonlinear response of irregular buildings under bi-directional horizontal ground motions, considering the Soil-Structure Interaction (SSI). A number of 3-D steel moment resisting frames with different levels of eccentricities in orthogonal directions are considered. One pair of TMDs with optimal parameters is placed at the roof level along two orthogonal directions. The optimal location of the TMDs in plan has been determined in a previous study. The infinite underlying soil medium is modeled by a discrete model using the concept of Cone Models. The shear wave velocity of the soil is varied to represent different soiltypes. Material damping of soil is also considered with some correction. These models are subjected to a number of bi-directional horizontal ground motions according to the soil type. Extensive parametric studies carried out to investigate the performance of TMDs in controlling the nonlinear seismic-induced response of the structural models, considering the SSI effect. Story shear forces and drifts are considered for comparison purposes. The OpenSees program is used for the required numerical analyses.

Tuned Mass Damper (TMD), Soil-Structure Interaction, 3-D Structural Models, Nonlinear Behavior