Assessment of the life cycle cost of Colombian hospital buildings retrofitted with buckling-restrained braces (BRBs)

Colombia has high seismic activity because it is located in the Nazca, South American, and Caribbean plate zones of influence. 83% of the population is located in intermediate and high seismic hazard areas. Many existing moment-resistant frame structures were constructed before implementing the Colombian seismic code, limiting their ability to respond to seismic events. The existing essential buildings, such as hospitals over 30 years old, do not have the structural capacity to resist earthquakes because they need to meet the requirements of current seismic design codes. The Colombian government has indicated that all hospital buildings built
before the Colombian seismic design code NSR- 10 must be retrofitted to guarantee their operability in a significant seismic event, making it necessary to consider alternatives for retrofit.
The use of buckling-restrained brace devices has gained more attention in recent years, thanks to its advantages for the design and retrofit of buildings due to its effectiveness in reducing damage to buildings associated with seismic forces. Currently, the Colombian seismic design code only contemplates conventional reinforcement methods, making it necessary to carry out research projects that evaluate the effectiveness of buckling-restrained braces as an alternative that allows the retrofit of hospital buildings and even other structures. In this investigation, it is
initially proposed to elaborate a documental analysis of the characteristics and the state of the existing hospital buildings to identify their structural properties; later, laboratory tests from the bibliography of the buckling-restrained braces are selected to characterize their behavior, and finally, perform an incremental dynamic analysis (IDA) to identify the efficiency of the use of restricted buckling braces for the retrofit of these buildings and calculate the probability of collapse for different seismic events through fragility curves. Finally, the life cycle cost analysis is carried out.