SR400 State of the art of timber-based hybrid seismic-resistant structures (September 2018)

The use of timber in the construction of multi-storey buildings in seismic regions has been gaining momentum around the world for several decades. As timber is a relatively new material for the construction of such structures, engineers face new challenges related to the evaluation of the behaviour of these structures during earthquakes.

There has been significant research conducted on structures made of light timber-framed (LTF) walls as well as massive timber such as laminated veneer lumber (LVL) or cross-laminated timber (CLT). However, there are still many questions that remain unsolved. Among those, the commonly accepted practice of relying on the dissipation of the seismic energy to take place in the connections needs to be revisited in the context of new paradigms such as robustness and resilience.

To achieve increased performance, the use of timber alongside other materials such as concrete and structural steel has been investigated in the past, leading to the term ‘hybrid structures’. Even though the existence of a minimum amount of hybridity in any building is difficult to deny, a structure where timber is intentionally used in conjunction with structural members of other materials is understood to be a timber-based hybrid structure.

This report presents a review of the current body of research on this topic. It covers experimental and numerical research, built applications, connections between elements and design methodologies related to hybrid timber structures. This report discusses the benefits and downsides of the previous research and applications to establish some background for new hybrid timber systems to be proposed and investigated by BRANZ in the future.