Seismic performance of a brick veneer steel-framed house

The use of high-strength, cold-formed steel frames in residential construction is steadily increasing in both Australia and New Zealand. One common form of this construction uses brick veneer as a cladding, where non-structural brick walls are attached to the structural frame via brick ties. Under earthquake loading there is a complex interaction between the frame and veneer walls. While there is a standard component test method for assessing the seismic capacity of brick ties, this method has been developed around brick veneer on timber studs and its application to the very different steel stud characteristics is inappropriate. In order to realistically assess the overall performance of brick veneer construction with steel framing, a full scale one-room test structure 'Test House' was tested on a shaking table. The Test House incorporated veneer walls with different geometries. It was subjected to varying levels of the El Centro earthquake ranging from moderate serviceability limit state ground motion to well beyond the design maximum considered earthquake for New Zealand. These levels of shaking were selected in order to ascertain the response for specific limit states to the Australasian Loadings Standard and to compare against minimum performance requirements. Comprehensive measurements on the frame and veneer walls were taken including acceleration, drift and differential movements between the frame and veneer. The Test House performed very well, with no brick loss up to 2.6 times El Centro (ElC) earthquake which is well in excess of all performance requirements.