Effect of Strength Reduction on Seismic Performance of the Steel Structures with Different Elevations

There have been considerable developments in techniques concerning seismic retrofitting of the structures in recent years which have been employed the same as the old ones. In this study, a new procedure with difference from common methods is proposed. The main objective of this procedure is to reduce simultaneously seismic requirements and maximum acceleration of the structure. Reducing seismic requirements of the structure, the lateral strength of the structure is decreased in the first step. Then, supplement damping devices are used to control the deformations caused by the first step. Fluid viscous damping devices are considered as inactive damping systems. Three moment steel frames with different elevation of 2, 4 and 7 stories were investigated using nonlinear static analysis (push over) and nonlinear dynamic analysis (time history). The results showed the reduction in base shear and decrease in acceleration induced on the structure as lateral strength. It is also concluded that, as the displacements are decreased by using damping devices, the performance of the structures has been improved significantly.