۱٫ Introduction

۲٫ Materials and methods

۳٫ THEORY/CALCULATION of the existing building response

۴٫ Results of the evaluation of the retrofitted building

۵٫ Discussion of results

۶٫ Conclusions

Acknowledgments

Appendix A. Supplementary data

References

Abstract

Several existing reinforced concrete (RC) buildings fail to conform with current seismic codes, increasing its susceptibility to damage and collapse during earthquakes. A concern for building upgrading and rehabilitation has grown considerably in the last decades. However, there is limited information related to the seismic performance of RC buildings retrofitted with steel jacketing. Retrofitting of RC buildings leads to different techniques that have been developed in the last decades. The selection of adequate techniques commonly depends on desired performance levels, financial criteria, or other non-technical judgment. This paper assesses the seismic performance of a six-story RC building retrofitted with steel jacketing that is located in Cartagena de Indias (Colombia). The building was designed and constructed in 2010 without considering the requirements prescribed by the NSR-10 Colombian code. In 2017, another building collapsed in the same city for several non-compliances with Colombian seismic code. This investigation focuses on the seismic upgrading of the building, studying the influence of different material properties of the existing building and load scenarios on the building behavior. The proposed steel jacketing improves the compressive and flexural capacity of retrofitted columns, along with the ductility of the building.

Introduction

Several existing reinforced concrete (RC) buildings do not conform to current seismic codes, even in regions of high seismic hazard. Therefore, many of these buildings are susceptible to damage and even collapse during earthquakes [1,2]. Structural and non-structural damages and poor performance of RC buildings with code non-compliances have been observed after recent earthquakes [3]. Most of these damages haven been evidenced in RC columns with insufficient axial/shear loads capacity given by inadequate longitudinal/transversal reinforcement and dimensions, 90-degree hooks for stirrups at both ends of columns, inadequate detailing in beam-column joint regions, strong-beam and weak-columns, soft stories, weak stories, and poor quality construction [4,5].

The concern for seismic upgrading and rehabilitation has grown in the last decades [2,6,7] following structural and non-structural earthquake-induced damages observed after relevant seismic events in different parts of the world like Northridge (1994), Kobe (1995), Kocaeli (1999), Sichuan (2008), Chile (2010), Ecuador (2016) or Mexico (2017). In Colombia, the government adopted the earthquake-resistant Code for construction in Colombia NSR-10 [8]. This code prescribes criteria and minimum requirements for the design, construction, and technical supervision of new buildings. Also, the code offers design and revision guidelines for those buildings indispensable after an earthquake.