Investigation of behavior factor for reinforced concrete structures by Viscous damper

Nowadays, finding ways to reduce earthquake force due to its damages is one of the most important challenges in the field of earthquake engineering. As a result, the selection of passive Viscouz damper is preferable due to its low cost advantage, more appropriate technology and commen use in country. In this research, the effect of Viscouz damper on seismic performance of concrete moment resisting frame has been investigated. For this purpose, three medium concrete moment resisting frames, which have3, 6 and 10-floors, are designed by the Sap2000 software without damper effect. Then, the damper has been analyzed by siesmo struct software. these frames have been designed by common methods, and then have been studied under the acceleration of selected earthquake mappings by using static pushover and dynamic time history analysis, with and without supplemental viscous dampers. Based on these studies, a value is suggested for the behavior factor of the damper added to the structure and compared with the values contained in the 2800 regulations. Also, this factor is investigated in structures equipped with this damper in far field and near field earthquakes. by including viscous damper, damping increases 20% .the suggested values of the behaviour factor for the static pushover and dynamic time history analysis are 6.29 and 6.23 respectively.