Out-of-plane behavior of brick wall of historical masonry structures

Aiming at the characteristics of masonry structures of historical buildings that brick walls are prone to out-of-plane damage and collapse subjected to earthquakes, four full-scaled unreinforced brick walls with return walls were designed and fabricated. Static test was carried out under out-of-plane uniform load applied using the airbag loading system. The out-of-plane failure mode and mechanical properties of the brick wall of historical buildings were studied. On this basis, by theoretical analysis, influence factors including vertical load, wall thickness, wall width, floor form, and mortar strength were analyzed and the calculation method of the out-of-plane bearing capacity of the brick wall was proposed. The results show that the out-of-plane failure of the brick wall is brittle, that is, the out-of-plane displacement increases rapidly following the peak load. Meanwhile, the brick wall can still maintain a large out-of-plane displacement without collapse after cracking. Compared with the brick walls without floor slab, the initial stiffness of the wooden floor and the concrete floor brick wall has increased by 69.9% and 68.8% respectively, and the out-of-plane bearing capacity has increased by 44.5% and 54.0%, respectively. In addition, the vertical load, wall width, and wall thickness have significant effects on the out-of-plane bearing capacity of the brick wall, the floor form has a certain effect, while the influence of mortar strength can be basically ignored. The theoretical values of the out-of-plane bearing capacity of the brick wall are in good agreement with the experimental results.