Experimental and Numerical Investigation of Out-of-plane Behavior of Masonry Brick Walls with Low-strength Mortar: Effects of Slenderness, Shape and Openings

<span style="color: rgb(51, 51, 51); font-family: &quot;Open Sans&quot;, sans-serif; font-size: 17.6px;">Masonry structures are traditional buildings made up of heterogeneous and anisotropic components, which create various challenges in design, construction and analysis. This study aims at investigating the out-of-plane behavior of walls constructed with low-strength mortar through both experimental and numerical approaches. In this context, the effects of wall slenderness, shape and openings on out-of-plane behavior were explored. Different wall slenderness ratios (height/length) and door/window openings were considered in the wall models. Masonry wall models were experimentally tested on a tilting table and further analyzed using ABAQUS software. Six wall models each of U, L and I shapes with two-side, one-side and no support respectively were constructed. Each model was tested at least twice and experimental and analysis results were compared. The results showed that increasing wall slenderness (from 1.33 to 2) led to 10–50% reductions in lateral load capacity, especially in U-shaped walls. More door and window openings further decreased capacity and enlarged failure zones. A single supporting wall increased capacity by 3.5 times, while two supports raised it 5.5 times. More ductile behavior was observed due to the supporting walls, which prevented early collapse. The findings emphasize the critical role of support walls in reducing capacity losses.</span>