Seismic Reinforcement System of RC Structure Using Eccentric Brace Frame

Abstract

This paper introduces an eccentric brace system (EBS) based on an energy dissipation device for seismic retrofitting. Particularly, an EBS-based seismic reinforcement method (SRM) is proposed, and a damper system is constructed based on this method by considering performance enhancement and cost reduction. In a column reinforcement test, the yield strength and maximum strength of a direct web connection test piece (reinforced only via the direct bonding of the web) were marginally lower than those of a plate and web direct connection (PWC) test piece (reinforced by the direct bonding of the column and steel plate). However, the yield strength and maximum strength of the direct web connection test piece were 2.17–3.09 times those of the unreinforced specimen. In addition, it was verified that the strength decreased by approximately 13–18% compared with that of the PWC test piece. Moreover, a significant strength improvement effect could be achieved even when the web of the H-beam was attached directly to the reinforced column. The plate strength improved moderately because of the installation of the additional plate. In addition, in a reinforced frame test, the yield strengths of the SRM-I (simple reinforcement frame) and SRM-II (shear reinforcement frame with K-type inserts) test pieces were 1.27 and 2.47 times greater than that of the reinforced concrete frame specimen. Further, the maximum strengths of the SRM-I and SRM-II test pieces were 2.22 and 2.95 times greater than that of the reinforced concrete frame specimen. The rate of reduction in stiffness for the reinforced concrete frame specimen was the highest and that for the SRM-II test piece was the lowest. A review of the crack pattern, load–displacement relationship, accumulated energy dissipation, and stiffness reduction rate revealed that the SRM-II specimen displayed the highest seismic performance.