Out-of-plane behavior of masonry infilled Chuan-dou timber frames

The masonry infilled Chuan-dou timber frame is a traditional structural system widely used for non-engineered residential buildings in southwestern areas of China, where earthquakes are common. And the masonry is prone to out of plane (OOP) collapse due to the lack of an effective connection between the timber frame and the masonry. This paper discusses the OOP seismic performance of masonry infilled wall Chuan-dou timber frame. Considering the slenderness ratio and the compressive strength of mortar, three full-scale single-story specimens were subjected to airbag loading to investigate the out-of-plane seismic behavior of the structural systems. Two typical failure modes of the structural systems including one-way bending and shearing slip were observed in the study. The results indicated that the slenderness ratio of the infilled masonry was inversely proportional to the bearing capacity of the structural systems. The columns have a limited effect on the constraint of infill wall while the beam can prevent the wall from falling out of the frames. And the OOP seismic behavior of the infill wall can be improved by strengthening the connection between the infilled wall and the frame. At the same time, the formulas for peak OOP load are presented based on a two-hinged arching/rocking pier mechanism.