Seismic analysis and strengthening of substandard RC beam-column joints constructed in bhaktapur

Abstract

Beam-column joints are sensitive and vulnerable elements in a seismic event. Damage of the beam-column joints result in the global damage which is undesirable with the code revisions and recent criteria and provisions, the older buildings designed as per the pre-revised codes may not fulfil the necessary criteria. In addition, the deficiencies caused in the joints in construction phase, due to lack of implementation of proper seismic detailing as dictated by design and code add up to more insufficiencies and vulnerabilities. Numerical model in ABAQUS is validated against an experimental exterior beam-column joint. Finite element analysis of the study beam-column joint is done and performance is checked based upon the loaddisplacement behavior and damage pattern in the joint. Various strengthening strategies like CFRP, steel jacketing and concrete jacketing are implemented, analyzed and evaluated. Type III joint has the highest load carrying capacity and better damage pattern as compared to the Type I and Type II joints. CFRP wrapping could not achieve the desired performance, however RC jacketing and steel jacketing retrofitting strategy had significant improvement in the performance of the joints