Seismic assessment of existing low-rise RC buildings: A case study

Modern and safe structures can be built depending on the developing materials and construction technologies. However, this is not possible for existing structures. Considering the losses occurring in time due to different reasons in the construction quality and material strength of the existing buildings during the construction period, it is necessary to determine the structural safety of these structures. This situation becomes even more critical, especially in areas prone to earthquake risk. It is a necessity to determine the earthquake safety of the existing structures in these areas with advanced analysis methods and to take the necessary repair / strengthening measures. The presented study covers the determination of the earthquake performance of an existing RC structure built as a residential building with advanced analysis methods based on the current regulations. In this scope, firstly, the existing building’s structural system, geometry, layout and material properties were determined by site surveys and lab studies to evaluate its seismic performance level. Secondly, the building was modelled by Midas Gen finite element software. In the analysis model, fiber hinges were assigned to the columns, and lumped hinges were assigned to the beams. In the last stage, the numerical simulations of the building is performed by modal analysis and pushover analysis to determine the seismic performance levels of before- and after- the excavation according to the current Turkish Building Earthquake Code (TBEC 2018). The maximum and minimum strain values formed in the column and beam cross-sections were calculated by the curvature values obtained from the related members’ assigned hinges. It is concluded that the case study will present an approach for the determination of the seismic performance of existing RC buildings.