Flanges’ Impact on Persian Historical Masonry Walls: Modeling Safety Factors

This comprehensive study investigates the nuanced impact of flanges, height-to-length aspect ratios, wall thickness, and pre-compression levels on Persian historical masonry walls under uncertainty conditions. Numerical testing of 100 masonry wall specimens, varying across five lateral constraints (flanges), four height-to-length ratios, three wall thicknesses, and three pre-compression levels, was conducted. The study also examined the influence of uncertainty on the modulus of elasticity. Results demonstrated a substantial dependency of ultimate shear force (Fu), ultimate drift (δu/H), and effective stiffness (𝐾𝑒ff) on the considered variables. Fu and 𝐾𝑒ff increased with higher lateral constraints, wall thicknesses, and pre-compression levels, decreasing with reduced aspect ratios. Simultaneously, δu/H decreased with higher lateral constraints, wall thicknesses, and pre-compression levels, increasing with reduced aspect ratios. Estimated values for Fu ranged from 292.5 to 1357.4 MPa, δu/H spanned from 1.61 to 3.43, and 𝐾𝑒ff varied from 7.72 to 158.9 kN/mm. Proposed partial coefficients for partial coefficients (γM), displacement capacity (γdu), and effective stiffness (γk) were introduced through models incorporating uncertainty, revealing that increasing lateral constraints and wall thicknesses, and decreasing aspect ratios, led to heightened values for γM and γk and reduced values for γdu. With increasing pre-compression levels, all safety factors increased. The safety factors (γM: 1.18–1.96, γdu: 1.16–1.76, γk: 1.157–1.967) optimize Persian historical masonry structures, providing crucial insights for varied conditions were proposed.