The Use of the Artificial Damped Outrigger Systems in Tall R.C Buildings Under Seismic Loading

Abstract

This paper studies the combination of fluid viscous dampers in the outrigger system to add supplementary damping into the structure, which purpose to remove the dependability of the structure to lower variable intrinsic damping. This optimizes the accuracy of the dynamic response and by providing higher level of damping, basically minimizes the wanted stiffness of the structure while at the same time optimizing the achievement.

     The modal considered is a 36 storey square high rise reinforced concrete building. By constructing a discrete lumped mass model and using frequency-based response function, two systems of dampers, parallel and series systems are studied. The maximum lateral load at the top of the building is calculated, and  this load  will be applied at every floor of the building, giving a conservative solution. For dynamic study Response Spectrum Analysis was conducted and the behavior of the building was determined considering response parameters. MATLAB software, has been used in the dynamic analysis for three modes.

     For all modes, it is observed that the parallel system of dampers result in lower amplitude of vibration and achieved more efficiently  compared to the damper is in series, until the parallel system arrives 100% damping for mode three.