A Study on the Seismic Behavior of Existing RC Hospital Buildings Strengthened with Steel Bracings

This study aims to study the seismic behavior of existing reinforced concrete buildings (hospital buildings) with the use of bracing to obtain a higher level of performance. The study uses a nonlinear finite element structural analysis method, namely pushover analysis, to obtain a capacity curve. The scope of the study is an existing building located in a high earthquake zone (Bandung Regency, Indonesia) with SDs values of 0.89 g and SD1 of 0.49 g. The types of bracing used in this study are concentrically braced frame types V- and X-bracing. Steel bracing is placed on the portal section of the weak axis direction with the aim of reducing drift to obtain a higher level of performance, namely immediate occupancy. The results obtained from this research indicated that the distribution pattern of plastic hinges first occurs in the beam for all three building types, so that it meets the criteria of columns being stronger than beams and no soft-story mechanism occurs. The results of the demand capacity ratio evaluation show building with V-bracing show a drift at a performance level of 0.0053 or 9.43% stiffer than building without bracing (existing building), while building with X-bracing show a drift at a performance level of 0.0054 or 7.94% stiffer than building without bracing. The novelty of the research is that the study of the use of bracing provides predictions of increasing the stiffness performance of the building, thereby supporting the function of the building as a hospital with an immediate occupancy performance level.