13-27 Manners Street 

13-27 Manners Street is a modern 15-storey commercial tower building in the heart of downtown Wellington.

The reinforced concrete tower building was built in the 1980s, and its primary weaknesses were the pre-cast floor units which lacked strength and were vulnerable to building deformation. Miyamoto provided seismic rehabilitation services to address the building deficiencies.

Traditional strengthening solutions would require invasive work to the interior. Miyamoto’s approach was to incorporate fluid viscous dampers into the existing concrete frame. By adding energy dissipation, building drift and acceleration reduced.

In the design, Miyamoto employed sophisticated structural analysis and laboratory testing of connection configurations and were actively engaged with the contractor to develop a resilient retrofit solution with a performance objective above Life Safety.

By adopting a higher performance criterion, the client can minimise time for re-occupancy and functional recovery, as well as direct financial losses following a seismic event.

In addition to the structural benefits, working only around the perimeter and isolated internal locations minimises downtime, disruption and refurbishment costs during construction.

Turnbull House 

Following on from case study paper at the 2024 NZSEE, there is the opportunity to visit Turnbull House, currently undergoing strengthening.

Turnbull House is a Category 1 Heritage building on Bowen Street in Wellington. It was built in the 1910s as a residence and library, primarily from unreinforced masonry. Although some strengthening was carried out in the 1950s and 1990s, it has been assessed as Earthquake Prone and so currently undergoing major programme of improvement. Construction involves extensive temporary works to facilitate installation of Triple Friction Pendulums below the Ground Floor, chosen to minimise disruption, cost and intervention to the heritage fabric above.