Abstract
Existing buildings designed on pre-seismic design philosophy as well as modern construction deficient frames may be susceptible to the effects of strong ground motions. Therefore, effective retrofitting is one of the solutions aimed to mitigate the seismic vulnerability of such buildings. This paper assesses the static and dynamic response of reinforced concrete frames strengthened with two of the most widely used methods; eccentric steel braces and reinforced concrete column jackets using an experimentally calibrated and validated finite element model. Results of a single-story frame under nonlinear static analysis are assessed in terms of performance and damage mechanism, hysteretic force-drift curves, capacity backbone curves and hysteretic damping. The jacketed and braced frames considerably enhanced the lateral maximum resistance approximately by 2.3 and 2 times respectively. Moreover, dynamic acceleration time history analyses have been performed on a low rise three-story bare and retrofitted frames under design base and maximum considered earthquake ground motions. Inter-story drift profiles for the bare, braced and jacketed frames have been achieved. The braced frame has been found to be more effective in reducing the inter-story drift demands approximately by 1.25 and 1.42 times under design base and maximum considered earthquake ground motions respectively as opposed to the jacketed retrofit solution. Both the retrofit solutions are effective in reducing the vulnerability of deficient frames and can be effortlessly implemented in developing countries in particular due to the easy availability of the commonly used materials compared to other retrofit methods.