seismic upgrading of the 111 serie residential 10 story r.c.frame buildings in armenia, using additional isolated upper floor

widely distributed 111 serie, 10 story r.c. frame buildings are constructed during former soviet union in armenia and nagorno karabakh province. current research is completed to illustrate the concept of seismic upgrading of above mentioned buildings, using an additional isolated upper floor (aiuf). after constructing the finite element model, time history analyses are applied on it, using six pair of accelerograms recorded on rock or very stiff soil (750<v_s<1200 m/s), and loose rock or stiff soil (375<v_s<750 m/s), scaled to s_a=0.4g. later, the aiuf which behaves as a tuned mass damper (tmd) is added to the model and after tuning for the frequency and damping ratios, the same time history analyses are applied on this new model too. the final analyses results show considerable reduction on lateral displacement and base shear force when using aiuf, satisfying the overall seismic behavior of the building.