Seismic vulnerability and retrofitting scheme for low-to-medium rise reinforced concrete buildings in Nepal

In this paper, seismic capacity assessment is presented for representative low-to-medium rise reinforced concrete (RC) buildings in Nepal. The structural behavior of buildings was studied with different analysis techniques and loading considerations. The non-linear behaviors of nine residential building structures were studied with finite element analysis. Structural performance is presented in terms of strength, stiffness, capacity curves, and inter-story drifts. The building models were analyzed as bare frames, and the drift profiles were compared with some standard drift limits to depict the vulnerability. Buildings noted as vulnerable after the analyses were modified as retrofitted using column jacketing technique, and finite element analyses were carried out again. Comparisons were made in terms of seismic performance of as-built and retrofitted buildings. The sum of observations depicts that column size directly affects the vulnerability of buildings. Moreover, column jacketing significantly ameliorates the seismic performance of low-to-medium rise RC buildings as depicted by the comparison between as-built and retrofitted structures in terms of inter-story drift and fundamental period.