Required Local Ductility for RC Frame Systems in Seismic Regions

According to Eurocode 8, reinforced concrete structures in seismically active areas should be designed to have adequate energy dissipation capacity and ductile behaviour. The capacity to dissipate energy is determined by the upper limit value of behaviour factor q. To achieve the necessary level of ductility in frame systems, the design of the longitudinal and transverse reinforcement in beams and columns must adhere to specific recommendations. The special provisions EC8 for local ductility in critical regions of beams and columns are presented. The standard recommendations are illustrated with examples analysing the ductility of reinforced concrete beams and columns under varying amounts of longitudinal reinforcement and different loading conditions. For this purpose, analytical and numerical methods were used. The local ductility of beams and columns in reinforced concrete frame structures significantly depends on the amount and distribution of reinforcement, as well as the influence of longitudinal forces.