FINITE ELEMENT ANALYSIS OF EXISTING RC BEAM-COLUMN JOINTS STRENGTHENED BY PRESS-JOINT WITH ADDITIONAL RC MEMBERS

Abstract

Only a few specialized research studies and examples of seismic strengthening methods for beam-column joints in existing reinforced concrete (RC) buildings exist. In a previous study, we proposed a seismic strengthening method that press-joints additional RC members around existing steel-reinforced concrete (SRC) beam-column joints. This study used finite element analysis to investigate the reinforcement effect of the proposed seismic strengthening method on existing RC beam-column joints. Initially, finite element analysis was conducted to imitate the assembled test in which the RC beam-column joint was fractured. The model analysis results agreed well with the test results. For this existing RC beam-column joint model, three types of models with reinforcement methods as parameters were analyzed. The first type model press-joints additional RC members only in the in-plane direction. The second type model press-joints additional RC members in the in-plane and orthogonal directions. The third type model press-joints additional RC members in the in-plane direction, and the additional RC members and existing part are joined by post-installed anchors in the orthogonal direction. According to results, cracks at the existing RC beam-column joints were confirmed to be reduced in the strengthened models. The model that press-joints additional RC members in the in-plane and orthogonal directions most significantly reduced the minimum principal stress in existing RC beam-column joints the most.