Lateral Behavior of Masonry-Infilled Wood Frames with Wood Diagonal Bracings of Different Forms

Masonry-infilled wood frame walls are widely used in vernacular buildings all over the world. Based on traditional European wood frame walls, this paper proposes wood bracing as reinforcement for traditional Chinese masonry-infilled wood frame walls to compensate for premature cracking of masonry infill and the resulting performance degradation of the walls. Five wall frames were prepared and loaded cyclically in lateral direction. Wood bracings of different forms and their contribution to the wall performance were studied. The hysteretic curves, stiffness and strength degradation, energy dissipation, and equivalent viscous damping coefficient were determined and discussed for their relationship with the bracing provisions. It was found that the bare frame was flexible and resilient and the masonry-infilled frame was stiff and prone to brittle failures, while the frames reinforced by wood bracing exhibited good load-carrying capacity, deformability, and energy dissipation capacity. The peak load and the ultimate displacement of the frame reinforced by X-bracing were 49% and 85% higher than those of the masonry-infilled frame, and the equivalent viscous damping coefficient was increased by 81% at most. The asymmetric Z-bracing and double crossing bracing led to a slight decrease in the initial stiffness compared to the masonry-infilled frame due to the pull-out of the intermediate mortise-tenon connections.