Advanced sustainable lateral load resisting systems that combine ductile and recyclable materials offer a viable solution to resist seismic load effects in environmentally responsible ways. This paper presents the seismic response of a post-tensioned timber-steel hybrid braced frame. This hybrid system combines glulam frame with steel braces to improve lateral stiffness while providing self-centreing capability under seismic loads. The proposed system is first presented. A detailed numerical model of the proposed system is then developed with emphasis on the connections and inelastic response of bracing members. Various types of braced frames including diagonal, cross and chevron configurations are numerically examined to assess the viability of the proposed concept and to confirm the efficiency of the system. A summary of initial findings is presented to demonstrate usefulness of the hybrid system. The results demonstrate that the proposed system increases overall lateral stiffness and ductility while still being able to achieve self-centring. Some additional information on connection details are provided for implementation in practical structures. The braced-frame solution is expected to widen options for lateral load resisting systems for mid-to-high-rise buildings.
Recently, Canadian building regulations have allowed construction of light-frame wood buildings up to six storeys. Even though equivalent static force procedure (ESFP) is generally used for the seismic design of such buildings, in cases of irregular structures and in high seismic zones a linear dynamic analysis (LDA) is required by the code. However, commercial software has not yet been adapted to the dynamic analysis of this type of structures. In this paper, a design procedure for light-frame wood shear walls using a braced frame model and LDA is proposed and the potential for design optimisation is presented for a six-storey light-frame wood building located in Quebec City in the Eastern Canada. Comparisons between the proposed LDA procedure and ESFP based on the shear distribution, overturning moments, interstorey drifts and total inelastic deflections are shown. Structural advantages of using the proposed LDA are demonstrated.