Experimental Evaluation of Brick Unreinforced Masonry Wall Out-of-Plane Capacity and Modeling Using the Yield Line Method

This paper presents a theoretical model to estimate the out-of-plane (OOP) force capacity of brick unreinforced masonry (URM) walls with strong units and weak joints by applying virtual work and yield line theories for homogeneous plates. The OOP force capacity of the wall was assessed by considering mechanical properties, support conditions, external axial load, and self-weight load. The ultimate vertical and horizontal moments were calculated according to displacement and force models, respectively, developed in previous works. These models consider wall and brick geometry, shear and compression stresses in the joint–brick interface, and support conditions of the wall. The theoretical model presented herein combines the previous models while adding the tensile strength ( \({f}_{mt}\) $f_{\mathit{mt}}$ ) of the mortar and assuming elastoplastic behavior of the ultimate moments in both directions. The proposed model constitutes a useful tool to assess the OOP force capacity of brick URM walls with one-way and two-way bending configurations. This paper presents results from experimental shaking table tests and test results from previously published works to validate the proposed model. The comparison between experimental and theoretical results revealed that the developed model predicts the OOP capacity if the appropriate information is available.