Investigation the Arrangement Variation of Viscous Dampers in Tall Steel Structure under Near and Far-Field Earthquakes

This study focuses on the effect of viscos dampers arrangement over the height on the control of seismic behavior of tall steel moment-resisting frame structures by considering nonlinear dynamic analyses. To this end, 2D steel moment-resisting frame with 15-story is selected as sample structure with special ductility. The seismic demand parameters (i.e. inter-story drift ratio and base shear) of the sample frame is evaluated under two sets of near and far fault ground motions, each of which including 3 records. In next step, the sample structure is retrofitted by viscous dampers in different arrangements over the height and the effect of each arrangement on the seismic response of the sample structure is studied.  The nonlinear dynamic time history analysis is utilized to derive the seismic responses of the case study structure. The results of the study demonstrate that the application of dampers leads to reduction of inter-story drift response and increase in base shear demand. Also, it was found that the arrangement of the dampers in top one-third height of the structure or uniform distribution of the dampers over the height gives more efficient result than other arrangement patterns, in terms of inter-story and base-shear demand control.   Finally, it is observed that the insertion of dampers in all of the stories, although reduces the drift demand more than other patterns, but increases the base shear demand by up to 40%.