Self-centring building systems are key to driving the next generation of mid-rise and high-rise construction—not just in single-storey buildings but also in traditional multi-storey and assembly-line prefab construction.
That is according to new research, known as Self-centering mass timber structures: A review on the recent research process, published in the journal Engineering Structures, which reports that earthquake engineers are now making major strides in developing new mass timber systems that not only save lives but also minimise reconstruction costs.
In recent years, countries in the “Ring of Fire” – those that are at the highest risk of major earthquake activity have updated building codes and standards to protect against future natural disasters – with timber-based systems allowing buildings to balance stiffness and lightness to “ride out major seismic activity” and “bend before it breaks.”
Last month, Wood Central reported that the University of Stuttgart used a new self-centring system as part of Wangen Tower – the world’s first fully-curved and windproof cross-laminated-timber tower in Southern Germany.
According to the study’s lead researcher, Fei Chen, a Professor of Structural Engineering at Shanghai’s Tongji University, “the concept of self-centring (SC) technology has been under development for over two decades…(and) in 2005, was first introduced in laminated-veneer-lumber structures” as part of the University of Canterbury’s Preslam project.
Often used in shear walls, self-centring systems perform better during earthquake shaking with lower damage and fewer residual deformations – in effect, they help with the repairability and functionality of the structures after major activity.
“In the design of SC systems, regardless of the construction material being concrete, steel, or timber, achieving a balance between self-centring and energy dissipation is crucial,” Professor Chen said, adding that whilst the majority of research to date has looked at laminated-veneer lumber, “there has been growing acknowledgment of the advantages of cross-laminated timber panels.”
First researched in the 1960s, self-centring systems have gained increased prominence as global regulators look to mitigate damage and residual drifts caused by significant quake activity. In effect, these systems achieve self-centring by either allowing for the controlled rocking of primary structural elements, commonly coupled with mechanical restraints and energy dissipation devices, or by including self-centring devices as prominent structural or supplemental structural members.
This push, in turn, has led the world’s largest building material suppliers—including Simpson Strong-Tie—to develop new types of “click and set” steel connectors used in “rocking wall systems,” now subject to the world’s strongest earthquake testing.
- To learn more about how researchers are now using self-centred technology to make mass timber buildings more resilient to seismic activity, click on Wood Central’s special feature.
