optimization of cable system form, used in concrete structures in order to rehabilitate them

in this paper the rehabilitation of concrete structures with a new system is considered. in this system pre- stressed cables with energy dissipating viscous spring dampers at the end of each cable, are used to increase structure lateral stiffness. cable system can be replaced with other system due to their high tensile resistance, their easy replacement, high speed performance, economical matters and so on. this system can be used to retrofit existing structures. using this system not only reduces stories relative lateral displacements considerably but also allows them to have nearly equal displacements. in other words lateral stiffness resulted form cable in each story can easily be set by changing the passing position of cable and floor, according to frame displacement results. two concrete frame structures one three and another six story buildings- were modeled with the sap 2000package and optimum of cable form was obtained. comparing flexural frame results with cable system optimized case showed that the most reduction in relative lateral displacement occurred in the stories which had maximum displacements in flexural frame system.