Development of seismic fragility functions for close-spaced reinforced masonry shear walls

Fragility functions for fully grouted reinforced masonry (RM) walls under in-plane cyclic loading conditions have been systematically developed in this study. Despite the structural advantages of RM over unreinforced masonry, such as increased strength and ductility, fragility assessments considering various damage states under seismic loads have not been adequately investigated. This study bridges this gap through an integrated approach, by combining experimental and numerical data of these walls to enhance the reliability and applicability of the fragility functions developed. The fragility functions of this research were developed from 152 experimental tests on RM walls, enhanced by robust numerical simulations for varied influencing parameters that were missing from the experimental data. The combined datasets facilitated the definition of three distinct damage states: immediate occupancy, life safety and severe damage, where each of them has been linked to specific levels of in-plane drift of walls, which are critical for predicting potential failure modes under seismic conditions. The determined fragility functions indicate that the shear dominated walls are more vulnerable under in-plane loading than the flexural walls. The fragility functions proposed herein represent, a critical advancement in the domain of performance-based seismic design, offering essential insights for the seismic vulnerability and potential losses assessment of RM walling systems. • A detailed experimental database was developed for close-spaced RM shear walls for drift analysis. • Gaps in the experimental database were analysed through numerical method. • Damage states were defined for close-spaced RM walls for seismic fragility analysis. • Seismic fragility was analysed for RM walls for H/L less than and more than 1.