Seismic Evaluation of Tall Buildings with End Shear Walls by Fragility Curve

Lateral bearing systems affect tall structures’ behavior against lateral forces. Shear walls are one of the influential structural members against lateral forces. However, the ends of shear walls undergo severe stress under lateral forces connected to a reinforced concrete shear wall called end shear wall to improve the end structure behavior of the shear walls. Adding the end shear wall by joining the ends of the shear walls strengthened the roof rigidity and decreased the stress intensity at the concrete core end. This study modeled two 30-story concrete structures with frame and reinforced concrete shear walls with and without end shear walls to evaluate the end shear walls’ behavior. First, the structure members were simulated in OpenSees to check the non-linear behavior. Then, the structures were subjected to remote domain records to examine the fragility curves. The results indicated that the end shear wall increased the maximum acceleration at maximum probability in low, medium, severe, and complete collapse states by 50, 28, 27, and 38%, respectively. The fragility curves showed a more appropriate behavior of the 30-story structure with end shear walls in low, medium, high, and complete damage states. This system is more efficient than others since the end shear wall cuts the initial period of the structure in half (from 4 to 2s in a 30-story structure with an end wall). This drastic decrease can add stories to the building. Stairs and elevators can be built into the structure instead of the end shear wall for more flexibility.