Far-field earthquake response examination of RC buildings equipped with fluid viscous dampers

Abstract

In the majority of seismic codes, the use of construction procedures to reduce the risks associated with seismic events is aimed at improving the resistance of structures by increasing their stiffness (as recommended in the Algerian anti-seismic code, RPA99/2003), while admitting a certain level of disorder. The recent history demonstrated (Boumerdes earthquake, Algeria, 2000 victims) that this method becomes ineffective when the structures responses are highly influenced by the shaking characteristics including the far-field, the near-fault, or quite high return frequency, especially in the case of major structures such as hospitals, civil defence barracks, etc., which must remain functional. The use of concepts to protect structures by reinforcing them with passive seismic energy dissipation devices has led to the appearance of a number of technics, such as the use of fluid viscous dampers (FVD). The present work aims to analyse the influence of passive seismic energy dissipation systems using fluid viscous dampers (FVD) on the maximum responses of reinforced concrete building exposed to far-field ground motions in terms of accelerations, displacements and different types of intern forces. Fast nonlinear time history analysis (FNA) with the employ of Boumerdes seismic signal of May 2003, were carried out using a computation software on a reinforced concrete building consisting of a ground floor and six storeys and fitted with FVD absorbers characterized by a linear force-velocity relationship. The results of the analyses performed to estimate the response of the RC frame with and without this type of energy dissipaters were discussed. The results highlighted the exceptional capacity of these absorbers to increase the dissipation potential of this type of building in far-field earthquake conditions without having to increase its rigidity by means of RC shear walls, thus reducing the quantity of materials required for its overall stability and its weight on the foundation soil.