Development of a simplified method for detailed seismic performance analysis of existing reinforced concrete buildings

Earthquakes have had significant impacts on humanity, causing immense destruction in many countries throughout history. Geological records and historical data indicate that earthquakes will continue to occur worldwide. Scientific studies indicate that all countries are at varying degrees of risk when it comes to earthquakes. The fact that approximately 95% of our country's land is located in regions with a potential for earthquakes, coupled with the majority of the population residing in these areas, further emphasizes the importance of designing our structures to be earthquake-resistant and evaluating the seismic performance of our existing building stock. Minimizing loss of life and property, protecting the country's economy, and managing the sociological impacts within society all underscore the necessity of determining the behavior, or rather the performance, of existing buildings under earthquake effects, and subsequently taking the necessary measures in the event of potential inadequacy. The complexity associated with predicting and interpreting rotations occurring at the ends of structural elements under the influence of earthquakes has led to the development of drift-based formulations in this study. The aim was to develop a reliable method for predicting building performance by relating the rotations at the element ends to displacements, based on shear force (V) and displacement (D). This approach addresses the challenges in determining the seismic performance of existing buildings, as estimating and interpreting rotations caused by earthquake effects are intricate. After determining the damage limits and damage states within the framework of the VD method, it was observed in the study that the length of plastic hinges significantly affects the seismic performance of columns. In order to ensure both safety and practicality, the plastic hinge length defined in TBDY2018 was adopted as a reference in this study. Four buildings with symmetric and regular geometries to match the existing building shape within the scope of the study, and the foundations of the formulations used in the developed method were laid based on their interpretations. After analyzing three buildings with regular geometry and three buildings with irregular and asymmetric geometry, it was found that the VD Method showed 100% compatibility with TBDY2018 in eight buildings. However, the compatibility was relatively lower for highly irregular buildings. Considering this level of compatibility, the VD Method was identified as an alternative technique for assessing seismic performance. The compatibility of the VD Method with commonly used structural analysis software was also examined, revealing that the proposed method remained on the safer side compared to other software packages while generally producing compatible results.