Ultimate drift prediction models of rectangular squat reinforced concrete shear walls

Abstract

This paper describes a comprehensive assessment of the ultimate drift capacity of rectangular squat Reinforced Concrete (RC) walls through collection of up-to-date experimental database. Axial-moment curves are used to categorise the walls into shear or flexural failure modes. Important parameters contributing to drift, i.e. shear span to depth ratio, axial load ratio, mechanical ratio of reinforcements and confinement effects are identified. Two drift prediction models distinctively for flexural and shear-controlled walls are calibrated through statistical multi-parameter regression analysis. These models demonstrate more reasonable drift predictions for squat walls compared to past models developed mainly for slender walls. Six squat RC walls were tested under high axial load ratio to affirm the reliability of the models to address the unique “squat” phenomenon in shear walls. The drift capacity of existing walls can be estimated and refined reinforcement details can be recommended for future consideration of seismic action in regions without statutory seismic design codes.