Progressive collapse analysis and seismic performance of irregular RC structures: a probabilistic approach

Progressive collapse analysis is crucial for evaluating structural integrity under extreme conditions such as sudden column removal. It aids in the development of robust design strategies, improves structural resilience, and informs decision-making for risk prevention and structural safety enhancement. This manuscript investigates the seismic performance and progressive collapse behavior of a G + 6 RC structure with irregular geometry. The study employs a probabilistic approach, utilizing SAP2000 V20 software for comprehensive analysis and design. The study begins with the linear static method, a simple yet effective analysis method that provides insights into the structures resistance against progressive collapse. The study then progresses to the nonlinear static method, which offers more accurate results for the behavior of a structure experiencing progressive collapse. The analysis aims to observe stiffness, and displacement of the building under different scenarios of column removal, simulating the effects of various extreme events that could lead to column failure. A key aspect of this study is the development of fragility curves for each of the six column removal cases. These curves, derived from progressive collapse analysis results, provide a probabilistic measure of the likelihood of failure given a certain level of stress, offering a quantitative measure of the structures vulnerability to progressive collapse. It reveals a higher collapse probability in scenarios involving the instantaneous loss of an exterior or interior column, suggesting a higher vulnerability to deformation during particular loading scenarios. According to the study's findings, progressive collapse analysis provides a logical and reliable way to evaluate the performance of structures with a high degree of irregularity. By providing techniques to increase the resilience of irregular reinforced concrete structures, the study's findings fill a gap in the behavior and performance of these structures under seismic threats and progressive collapse. This manuscript contributes to the ongoing efforts to enhance structural design practices and standards, particularly in the face of seismic events.