Shake table tests on single-storey braced timber frames

Abstract

Concentrically braced timber frames are often used as lateral load resisting systems in wood buildings where large open spaces are required. For application in high-risk earthquake zones, however, the ductility of the system is a concern, since energy absorption is typically limited to the connection region. In this paper, results are presented from a series of shake table tests conducted on single-storey braced frame models with different connections. Diagonal braces with five different connection types were tested, four of which used bolts as fasteners, while one brace had timber riveted connections. Four of the connections had a matching set with an identical configuration that was previously tested quasi-statically. Findings from the tests are presented along with some comments on the seismic behavior of this type of structural system. It was found that the seismic response of the braced frames is highly influenced by the brace connections. Braced frames with small diameter (slender) bolts and timber rivets showed desirable seismic performance, as they were able to dissipate the highest amount of the seismic input energy. A comparison of the quasi-static and shake table tests revealed slight differences in the load–deformation properties of the brace connections.Key words: braced timber frames, seismic response, connections, timber rivets, bolts, ductility, shake table tests.