The influence of flanges on the in-plane performance of URM walls in New Zealand buildings

The influence of flanges (return walls) on the in-plane lateral behaviour of unreinforced masonry (URM) walls is reported. Experimentation was conducted on clay brick masonry walls designed to replicate typical New Zealand construction in the early 20 Century and with flanges of different lengths and at different locations. Testing of URM walls showed that the presence of flanges has a significant effect on the in-plane response of the wall. The results of experimentation were compared with analytical results determined from previous research, with a high level of correlation. Consequently, it was concluded that the existing analytical model was suitable for determining the response of walls with flanges responding in-plane. Drift limits are also proposed, depending on the in-plane wall failure mode.