A study of the out-of-plane performance of brick veneer wall systems in medium rise buildings under seismic loads

摘要

Brick veneer wall systems have been damaged under severe out-of-plane seismic and wind loads. Consequently, the out-of-plane behavior of these wall systems has been investigated under both static and dynamic loading, but with a focus on low-rise buildings. This paper investigates the out-of-plane seismic performance of these wall systems in medium-rise buildings. Current prescriptive code requirements for these systems are evaluated in typical medium-rise steel and concrete building frames. Analytical models of the building frames and the veneer wall systems are developed. These combined frame and wall system models are subjected to the design based and maximum considered earthquake levels of selected ground motions. A parametric study was conducted over the range of stiffness and strength of these systems encountered in common US construction practice. An incremental dynamic analysis was performed until the models became unstable. Using this approach, it was possible to identify the component of the system that would potentially lead to its "Failure" or "Collapse".As a result of this analysis, it was concluded that the current prescriptive code requirements for masonry veneer wall systems are adequate for seismic loading in the critical out-of-plane direction. The analysis also found that the code provisions are quite conservative for flexible frames. As the frame flexibility decreased, the conservatism of the provisions also decreased, and were found to be much less conservative for the stiffest frame system investigated.