Investigation of Dynamic Shear Amplification of Cantilever Wall Systems

Abstract

Reinforced concrete structural walls are widely used in design of the lateral load resisting systems. Reinforced concrete structural walls allowed to economic and architectural designs in accordance with directions in especially multistory reinforced concrete building systems. Design shear forces are assumed to be proportional to the design base moment in the traditional design of structural walls that are based on forced based methods. However, studies reveal that considerable wall shear forces develop during nonlinear response due to higher mode effects that are not predicted by the force based design methods. This situation can lead to significant errors in the design. In this study, in order to prevent errors, dynamic shear force amplification factor had been studied to obtain by using real seismic accelerations. In this parametric study, 4,8 and 16 story typical wall buildings were designed for covering strength reduction factors of R=2,4,6,8 and 10 using Mode Superposition Method that forcebased method. Designs were taken into consideration 1st earthquake area and Z3 local site class in Turkish Seismic Design Code (2007). Designed walls were analyzed with nonlinear time history analyses and the dynamic shear force amplification factor () were obtained from the base shear forces were proportioned the design base shear forces. As a result, relations among strength reduction factor (R), first mode period and dynamic shear amplification factor () were determined.