On the Performance of 2 passive TMDs in Reducing the Seismic Response of 3-D Structural Models Considering the Soil-Structure Interaction

摘要

The application of passive or active Tuned Mass Dampers (TMD) in reducing the seismic or wind induced response of structures has been extensively explored in the literature. On the other hand, the effect of Soil-Structure Interaction (SSI) for the structures located on soft soil, on their dynamic parameters such as natural frequencies, damping ratios and modal shapes can be prominent. This paper investigates the effect of SSI on the performance of a couple of Tuned Mass Dampers (TMD) in reducing the seismic response of the structures situated on soft soil. A number of 3-D steel moment resisting frames with different eccentricities in orthogonal directions are considered. Two TMDs are implemented at the roof level in the orthogonal directions.These models are assumed to be located on a square rigid concrete mat footing, and the underlying soil is considered as a homogeneous half-space. Also, a Cone model has been used for mathematical modeling of the infinite soil medium. The shear wave velocity of the soil is varied from 150m/s to very large velocities to represent different soil types. These models are subjected to a number of bi-directional (horizontal) earthquake excitations according to the site soil type. Using the optimal location of these TMDs in plan from a previous study, their performance in controlling the seismic response of the structural models is studied considering the SSI. The criterion for investigating the performance of TMD in this study is the amount of the reduction in the maximum real story drift. The real story drift is calculated by vector summation of story drift in two orthogonal directions at any time instant. As the result shows, excluding the SSI effect could overestimate the TMD's performance.