Seismic Vulnerability Assessment of Regular and Irregular Reinforced Concrete Shear Wall Buildings Using Fragility Curves

This research explores the behavior of buildings with reinforced concrete shear walls during strong earthquake ground movements, with a specific focus on how they perform during collapse. The study examines the impact of irregular building plans, dimensions of shear walls, and reinforcement details on their vulnerability to collapse during earthquakes. The buildings are designed according to Iraqi building codes, with additional provisions for capacity design and dynamic amplification. Shear walls are modeled using a multiple vertical line element model that accounts for shear-flexure interaction and uses nonlinear hysteretic material models. Incremental dynamic analysis is employed to simulate the collapse of three-dimensional building models under increasing intensity levels of far field ground motion records from FEMA P695. The study considers plan irregularities of 5%, 8%, and 12% in the design. The results showed that for a constant PGA value of 0.68 g, the probability of failure increases from 83.5 to 98.2% as irregularities in the design increase from 5 to 12% which highlights significant impact of plan irregularities on structural performance during earthquakes.