Effect of Shear Wall's Eccentricity on the Seismic Performance of RC Dual Structural System

Reinforced concrete (RC) structural walls are effective for resisting lateral loads induced by earthquakes on building structures. They provide substantial strength and stiffness as well as deformation capacity needed to meet the demands of strong ground motions. In some cases, because of architectural limitations and/or formwork difficulties, the web of shear walls is constructed with an eccentricity with respect to the frame axis. The provision of shear wall's eccentricity may be needed for strengthening of existing building as well. However, most of the reinforced concrete code of practices such as ACI-۳۱۸-۰۵ and Iranian concrete code (ABA) have no recommendation(s) and/or limitations concerning this eccentricity. In this paper, the effect of Shear Wall's eccentricity on the seismic performance of RC dual system is studied. For this purpose, three two-dimensional (۲D) frames with ۶, ۹ and ۱۲ stories were selected from three-dimensional (۳D) buildings, which were analysed and designed according to the third edition of Iranian standard ۲۸۰۰ and ACI-۳۱۸- ۰۲ concrete code of practice. The nonlinear time history and nonlinear static analyses carried out for three different amounts of eccentricities. ABAQUS finite element program is utilized for nonlinear static and time history analysis. To calibrate numerical modelling, experimental results were compared with numerical model results which show good agreement, making sure that the computer numerical simulation of this study is satisfactory. The results indicate that by increasing the eccentricity, the torsional moment of boundary elements and the on-plane bending moment of shear wall significantly increase. In addition, shear wall's eccentricity causes on-plane shear in shear wall.

Keywords:

RC Shear Wall , Nonlinear Static Analysis , Nonlinear Time History Analysis , Eccentricity , Seismic Performance