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This paper deals with the optimization of the tuned mass damper (TMD) with different objective functions for high-rise building under earthquake motions considering soil–structure interaction (SSI). A study is conducted to search for the TMD that outperforms five objective functions (i.e., OF-1–OF-5) containing combinations of the structural responses and foundation responses. The main goal of the present study is to evaluate and compare the control performance of these five objective functions. The optimum parameters of TMD are obtained by particle swarm algorithm (PSA) to minimize the acceleration transfer function. To determine the dynamic response of a 40-story building under the influence of SSI, six different foundation soil conditions and eight different earthquake records are considered. The results show that the SSI effects on the dynamic response of the high-rise building resting on relatively soft soil types such as S D and S E are of critical importance. It is shown that the effectiveness of the optimum TMD designed by OF-1 is better than the others in suppressing the peak response values for all soil types. After OF-1, the best performances are obtained for OF-3 and OF-5 which yield approximately the same effectiveness. It is also found that different earthquake records, soil types and objective functions are very effective on the effectiveness of TMD.

The main goal of this paper is to investigate the influence of the earthquake frequency content on the optimization of tuned mass damper (TMD) for multi-story buildings. Earthquake frequency content is divided into three groups (i.e., low, intermediate and high frequency content) according to the ratio of peak ground acceleration to the peak ground velocities. Time-domain analyses are performed to obtain the dynamic responses of 10-story and 40-story shear buildings equipped with a TMD under twelve different earthquake records. Advanced firefly algorithm is used to obtain the optimum parameters of the TMD such as the frequency ratio and the damping ratio. The optimization criterion is selected as the minimization of the maximum top story displacement of the building with TMD. The optimum parameters of TMD designed by this paper and its control performance are compared with those of other previous works available in the literature. Compared to the other methods, the optimum TMD designed by this study especially performs better in reducing the maximum top story displacements. Furthermore, it is discussed why TMD is ineffective in reducing the maximum floor accelerations of 40-story building, and then the effect of different mass ratios and objective functions in reducing the maximum responses of both buildings under critical earthquake excitation is investigated in detail. The results also show that the frequency content of earthquake ground motions has a significant effect on the optimum parameters of TMD and its control performance.

The fixed base approach is widely used to obtain the seismic behaviour of Square Hollow Section (SHS) joints in a lattice girder. However, in some cases where soil-structure interaction (SSI) can be relatively significant, this approach may result in incorrect acquisition of the natural periods and dynamic responses of the lattice girders using welded tubular joints. This situation may negatively affect the safety of the structure by causing an underestimation of the dynamic loads acting on the structure. Therefore, this study evaluates the seismic behaviour of SHS joints in a typical lattice girder exposed to different ground motions considering SSI. A nonlinear finite element analysis software, Abaqus, performs the dynamic analyses considering six earthquake excitations with three different frequency contents (a ratio of peak ground acceleration (PGA) to peak ground velocity (PGV)) and four different soil types. After verifying the numerical model, it is determined that 3D solid elements should be used to capture the actual seismic behaviour of the tubular joints in a steel truss frame with or without SSI. A comprehensive parametric study is then carried out to evaluate the peak displacement and stress values on the SHS joints with and without SSI under different ground motions with different PGA/PGV ratios. The findings show that the stresses are concentrated around the column and bottom chord connection region. Besides, the SSI mechanism significantly affects the peak stress and displacement values of the SHS joints, especially in soft soil types. Furthermore, it is observed that the PGA/PGV ratio significantly changes the seismic responses of the steel truss frame.