Performance-Based Design of Tall Reinforced Concrete Core Wall Buildings

Reinforced concrete (RC) walls are commonly used as the primary lateral-force-resisting system for tall buildings, although for buildings over 49 m (160 ft), IBC 2006 requires use of a dual system. Use of nonlinear response history analysis (NRHA) coupled with peer-review has become a common way to assess the expected performance of tall buildings at various hazard levels to avoid the use of a backup Special Moment Frame for tall buildings employing structural walls. Modeling of the load versus deformation behavior of reinforced concrete walls and coupling beams is essential to accurately predict important response quantities for NRHA. It also has become important to assess the impact of the floor diaphragms, gravity framing system, and foundation system on the expected performance, as well as to compare the expected performance of code-compliant and performance-based designed buildings to assess the merits of using a performance-based design approach. Given this critical need, an overview of modeling approaches used for RC core wall systems is reviewed to assess the ability of common modeling approaches to accurately predict both global and local responses. Application of fragility relations within a performance-based framework is reviewed for selected components and analytical studies are used to address system level issues such as the impact of slab coupling on gravity column axial loads and higher mode impacts on wall moment and shear demands. Based on the results, recommendations for performance-based design are made and research needs are identified.