Nonlinear earthquake response of reinforced concrete frame wall dual systems

Abstract

The purpose of the study is to evaluate the viability of the response modification factor,R for frame-shear wall dual systems as specified in the new seismic draft code (July1994) and to check the behaviour of such systems under real earthquake motions.In the first stage of the study, typical frame-shear wall dual systems are designedaccording to Turkish Standard (TS500) Code and the New Turkish Draft Seismic Code(July 1994). The design is based on the 'strong column-weak beam' requirementspecified for ductile reinforced concrete frames and on the particular requirementsspecified for shear walls as stipulated in the draft code.Following the design of typical dual systems, a nonlinear monotonic analysis isperformed using the computer program IDARC2D. The program analyses the systemsunder monotonically increasing lateral loads corresponding to the single-mode analysisdefined in the draft code and produces structural response curves.The results obtained from monotonic pushover analyses have confirmed the viability ofthe response modification factor (R=6.5) specified in the code for a ductile dual systemprovided that the shear walls share a minimum amount of total base overturningmoment.In addition to monotonic pushover analyses, nonlinear time domain analyses of a typical10 storey dual system subjected to two most recent earthquakes (Erzincan earthquake,Turkey and Kobe earthquake, Japan) are performed. The results have shown that thestructure has reasonable overstrength. The ultimate deflection mode has not indicatedany storey failure mechanism.