بهسازي لرزه اي يك ساختمان هفت طبقه بتن مسلح موجود به كمك بادبندهاي فولادي محور

Seismic Rehabilitation of a 7-Story R.C. Building

Adding concentric steel bracings is a simple and adequate method for retrofitting of moment frame RC buildings, since any other retrofitting methods (including adding shear walls or FRP) seems to be impossible and sometimes very expensive. But concentric steel bracings have high stiffness and low ductility and sometimes cause architectural problems in buildings. Hence, the arrangement and position of these bracings must be studied in detail in order to select an optimum retrofitting method. In this article, vulnerability studies and retrofitting method of a 7-story R.C. building with medium moment frame system in Semnan city is investigated. This building is a flat slab system with low height beams and according to 3rd edition of standard No. 2800 needs to be retrofitted. On the other hand, with adding steel bracings at different levels of existing RC building and with regard to structural performance levels, the optimum retrofitting method must be selected. Nonlinear static analyses are performed according to FEMA-356 and ATC-40. Details of retrofitted elements are also presented in this paper.