SEISMIC RESPONSE OF HIGH RISE BUILDINGS USING FRICTION DAMPER By Endrita MULLETI Tirana, February

Abstract

Earthquakes present the biggest natural hazard faced in the zones with high seismicity. During recent years, historical seismicity data of Albania, shows a high number of small earthquakes, sparse medium – sized earthquakes (magnitude M 5,4 – 5.9) and rare large earthquakes (magnitude M > 6.5); and hence no seismic provisions have been incorporated into the existing buildings. The purpose of this study is to evaluate the seismic response of high rise buildings by using friction dampers. The finite element method (ETABS) is used to evaluate the behavior of the structure equipped by these devices. Two different methods of analyzing (Free Vibration and Time History analysis) have been done to accomplish this objective. In general, this study shows that friction dampers help to reduce story drifts, reduce accidental torsional motions of tall buildings, reduce axial loads of columns and beams, shear load and bending moment of beams, and base shear; reduce vibration amplitude and increase damping ration (the input energy dissipation). In this study, the seismic performance of the “Sinani tower” building is taken into consideration. This is a 9 story poly-functional building, 1 underground story, 29.6 m in height. The seismic survey is compiled by the Seismology Engineering Department at the Academy of Science. The object is located in an area with the expected seismic intensity with magnitude 7.5 MSK-64. The core focus purpose in this study, is to show how the implementation of friction dampers will improve the seismic response of this object. After the free vibration analysis and time history, the results show that the period, displacement of story, axial load of columns, shear load of beams and bending moment of beams of the damped structure is considerably reduced.