Detailed assessment study and concept retrofit design of existing typical RC buildings in Turkey by eccentrically steel braced frames

Abstract

The seismic performance of selected typical exciting RC buildings in Turkey retrofitted by eccentric steel braces is investigated. Briefly, non-ductile reinforced concrete (RC) buildings have been classified into low-rise (4 story), mid-rise (7 story) and high-rise (10 story) buildings. Lateral resisting contribution of the eccentric steel bracing in rehabilitating the building has been examined. The effect of steel bracing distributed over the height of the RC frame on the seismic performance of the rehabilitated building has been studied. In terms of estimating the actual behavior of the buildings during the seismic activity, to evaluate seismic performance levels of the existing buildings two procedures have been selected from FEMA 356; “Linear Dynamic Analysis” and “Nonlinear Static Analysis”. The performance of the building is evaluated in terms of story drifts and damage indices. The aim of this study is making detailed assessment of existing buildings and introducing eccentrically braced frames as an effective retrofit strategy. In the case study, unlike most of the rehabilitation methods which aim to locate shear walls in the building, implementing eccentric steel braces into RC buildings. Although there are some studies and even applications of adding EBF and concentric braced frames (CBF) systems into RC buildings, especially in these studies where EBF have been used as retrofit strategy, link element has been designed vertically and out of RC framing system. In this study link element has been modeled and designed as a box section around RC beam, for further studies it is recommended that link element should be RC beam instead of steel beam.