Ahmed Ashour and Khaled Galal
Ahmed Ashour, Assistant Professor, Cairo University, Dept. of Civil Eng., Cairo, Egypt. Former Postdoctoral Fellow, Concordia University, Montréal, Québec, Canada, H3G 2W1, eng.ahmed3ashour@gmail.com
Khaled Galal, Professor, Concordia University, Dept. of Building, Civil and Environmental Eng., Montréal, Québec, Canada, H3G 2W1, galal@bcee.concordia.ca
ABSTRACT
The lateral load-displacement response of reinforced masonry shear walls (RMSWs) has been extensively studied experimentally over the last decades. However, few simple analytical loaddisplacement models, exist in the literature, capable of predicting the complete RMSW response including the RMSW post peak behaviour. In this study, a backbone model is proposed capable of predicting the load-displacement relationship for flexure dominated RMSWs up to 20% strength degradation. The proposed backbone model is a quad-linear connecting the origin point with four key points corresponding to crack initiation, yielding, ultimate strength and 20% strength degradation. This study builds on the model proposed by Ashour and El-Dakhakhni [1]. A stressstrain material model for masonry and steel is utilized in the current study. Moreover, the model predictions were calibrated and validated against twenty-five RMSW tested under quasi-static cyclic loading having various shear span to depth ratio, vertical and horizontal reinforcement ratio and levels of axial stress. The model results show an overall acceptable level of accuracy including the post peak response. The RMSW lateral force corresponding to the four aforementioned points were perfectly predicted utilizing the proposed material models. Furthermore, it can be inferred that a simple reduction factor (i.e. computed from simple regression) multiplied by the RMSW stiffness at different level of loading can be used in calculating the corresponding RMSW displacements. The model procedure is simple, and the predictions are promising. Consequently, this model can be adopted in different design and assessment frameworks.
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