Seismic Design and Performance Assessment of a Super Tall Concrete Core Wall Building in Istanbul

Seismic performance of a 62 story reinforced concrete core wall building designed with the performance based seismic design principles is assessed in this study for identifying the basic design requirements affecting its seismic design. The building is constructed in Istanbul where seismic hazard is high. Its seismic design is almost entirely controlled by the internal force demands obtained under the 43-year design earthquake, with few exceptions. These are the axial stress limits on vertical members, minimum reinforcement limits for the core wall, and amplified shear demands in the cantilever core under the 2475-year earthquake ground motions. It has been found that almost all of the controlling design requirements lead to significant overstrength in design. However, the outcome is a significantly higher seismic performance under the 2475-year earthquake ground motions compared to collapse prevention level. The tall building displayed the desired seismic performance under these ground motions with reasonable inelastic response at the coupling beams and at the designated locations of the core wall. Yet the reflected cost of overdesign can be considered negligible when compared with the overall building cost.