The Use of Steel Damper for Enhancing the Seismic Performance of R/C Frame with Soft First Story

摘要

The responses of reinforced concrete frame building having soft first story under three selected earthquakes record is presented. The soft first story is characterized by the open space on the ground floor, while the story above having infill walls. In order to improve the seismic responses of r/c frame building, the steel damper of flexural type are installed into building on the first story. The finite element method is employed to simulate the response of the frame building subjected to selected severe earthquakes using non-linear time history analysis. The equivalent three strut model is adopted to account the interaction of masonry infill with structure members on building responses, and the presence of the opening in reduction both stiffness and strength of the masonry infill are also considered. The simplified tri-linear model of stress–strain relationship is applied to account for the nonlinearity of the equivalent strut material, while hysteretic behavior of steel damper approximated by a bilinear model. In addition, the inelastic behavior of beam and column elements with rigid end zone is also adopted. Furthermore, the results are obtained from nonlinear analysis to be used for comparison the seismic performance of the building under consideration. Finally, it was clearly noticed that the use of steel damper not only to avoid the premature collapse of building but also to increase the seismic performance of the soft first story buildings significantly.