Abstract

Cumulative shear wall overturning (CSWO) is a common response of structural models of multistory Light-Frame Timber Buildings (LFTBs) under lateral loads. Governed by holdown uplift and shear wall (SW) bending, large CSWO occurs in LFTBs due to the light self-weight of wood and the dominant rocking flexibility of stiff SWs. Even though CSWO is paramount in seismic design because of its effect on the flexibility of LFTBs (making hard to achieve the inter-story drift limits), this phenomenon is not incorporated into the structural models of LFTBs. For instance, in the design of LFTBs for lateral loads it is assumed that SWs behave as planar isolated elements. However, CSWO may be influenced by 3D coupling effects (3D-SWCE) in non-planar SWs such as T or L assemblies. This paper describes a large full-scale experiment of a 7.32 m x 5.1 m assembly, performed to gather insight into 3D-SWCEs through the cyclic evaluation of a non-planar T-shape SW. Results showed an asymmetric behaviour of the T-shape SW with increments of 20% and 98% in elastic stiffness and maximum capacity, respectively, with respect to those of a planar SW. It is concluded that 3D-SWCEs have a significant structural influence on the response of LFTBs.