Tūranga design rewrites resilience book

Innovative engineering solutions have been used in the construction of Tūranga, boosting resilience and minimising damage during a large earthquake.

The new central library will benefit from the cost-effective alternative technology developed by University of Canterbury Associate Professor Geoffrey Rodgers.

UC Associate Professor Geoffrey Rodgers in front of Tūranga.

The low-damage structural engineering design solution utilises “dampers” to both absorb energy in a big earthquake and prevent building damage.

Tūranga features large extrusion dampers, strategically bolted between key base walls and the foundation to act as motion restraints during an earthquake.

In all, 20 one metre-long dampers – each weighing 185 kilograms – have been used.

“Under a low level of shaking, this building will respond just like a fixed base structure,” Associate Professor Rodgers says.

“Once you get beyond that low level of shaking, it has been designed to roll and move at the base, but in a controlled way.”

A conventional approach would have been to incorporate sacrificial design features to absorb energy and prevent building collapse.

Associate Professor Rodgers says “it’s a solution that saves lives, but still results in high repair costs”.

The alternative design solution has also been used in Forte Health’s central Christchurch building, with 96 extrusion dampers installed throughout the structure.