INVESTIGATION OF A COST-EFFICIENT RETROFITTING STRATEGY OF AN EXISTING REINFORCED CONCRETE BUILDING

Abstract

In the decades of 1950s, 1960s, 1970s, and 1980s most of the buildings in Cyprus, an island in the Mediterranean Sea which is located to a high seismicity region, were designed without seismic design criteria and detailing rules for structural systems ductility, including a lack of supervision and an inadequate quality control of construction works. Most of those buildings are now dealing with a variety of technical issues due to the irregularity in concrete strength, carbonation of the concrete and steel reinforcement and minimal use of transverse and longitudinal reinforcement of the structural elements. Consequently, it is crucial to identify and retrofit the structures that require seismic upgrading. This work presents a case study of an existing reinforced concrete building in Cyprus that was built in the 1980s and had one of its roof floor cantilevers fail. Firstly, this study focuses on identifying critical failures using nonlinear pushover static analysis, and secondly, it investigates different retrofitting strategies and identifies the most practical and cost-effective approach for seismic retrofitting. These approaches include retrofitting with combined infilled walls and concrete jacketing and combined brace-frame systems and steel jacketing for seismic integrity.