Multi-level nonlinear modeling verification scheme of RC high-rise wall buildings

Abstract

Earthquake-resistant reinforced concrete (RC) high-rise wall buildings are designed and detailed to respond well beyond the elastic range under the expected earthquake ground motions. However, despite their considerable section depth, in terms of analysis, RC walls are still often treated as linear elements, ignoring the effect of deformation compatibility. Due to the limited number of available comprehensive experimental studies on RC structural wall systems subjected to cycling loading, few in-depth analytical verification studies have been conducted. Motivated by the increasing need for more accurate seismic risk assessment of high-rise buildings in multi-scenario seismic regions, a multi-level nonlinear modeling verification scheme is presented in this paper to investigate two different nonlinear modeling techniques for shear walls (2- and 4-noded fiber-based elements). The investigated modeling approaches and their key parameters are verified against the results of Phase I of uniaxial shaking table specimen tests (performed at the University of California, San Diego) on a seven-story full-scale RC shear wall structure under base excitations representing four earthquake records of increasing intensities. Three numerical models are created using two different tools (ZEUS-NL and PERFORM-3D). The results obtained from the numerical models are compared with the experimental results both on global and local response levels (top displacement, interstory drift, story shear force, story bending moment, period elongation and rebar tensile strain). The study reveals the superior performance of 4-noded fiber-based wall/shell element modeling approach in accounting for the 3D effects of deformation compatibility between lateral and gravity-force-resisting systems. The study also highlights the sensitivity of attained results to the stiffnesses assigned to the rigid links and 3D joints required to connect the shear walls to neighboring elements when a 2-noded element is used.