Seismic Vulnerability Assessment of Low, Mid and High-Rise RC Buildings Subjected to Near-Fault Earthquakes Using Fragility Curves

<div dir="ltr">In this study, seismic vulnerability fragility curves were developed for special RC moment-resisting frames with 3, 7, and 15 stories, corresponding to low-, mid-, and high-rise buildings as defined by the HAZUS-MH 2.1 guidelines. The 2D frames were modeled and analyzed using nonlinear time history analysis in OpenSees software, subjected to 14 near-fault ground motion records. The interstory drift ratio was considered as the damage index. The drift limits specified in the HAZUS guidelines were used to define slight, moderate, extensive, and complete damage states based on the structural system type and the number of stories, in order to generate fragility curves. The analytical and numerical investigations revealed that, in the 3-story frame, the increase in damage levels relative to the slight damage level was 1.76, 4.71, and 14.58 times for moderate, extensive, and complete damage levels, respectively. For the 7-story frame, these increases were 0.98, 5.36, and 11.37 times, while for the 15-story frame, the corresponding values were 1.2, 2.34, and 7.46 times, respectively. Overall, it can be concluded that with an increase in the number of stories and Peak Ground Acceleration (PGA), seismic fragility increases. However, the 15-story frame exhibited the least probability of complete damage compared to the 7- and 3-story frames, whereas the 3-story frame experienced the highest likelihood of slight damage among all.</div>