New base isolators for Christchurch building
Base isolators have been around since the 1970s in New Zealand, helping reduce the impact of earthquakes on buildings, but a new Christchurch building is going a step further.
David and Anna Abbott's 53 Victoria St rebuild will use a base isolator technology not used in the country before.
The couple are putting up a $6.4 million three-storey office and retail building opposite Christchurch Casino after the earthquakes destroyed the low-rise buildings on their 1140 square metre site.
They have already signed tenants including eateries Aroy Thai and Yamagen restaurant, and law firm Taylor Shaw.
Instead of lead rubber bearings, the building's shock absorbers will use double concave slider bearings.
Grant Wilby, technical director of Aurecon which is engineering the building, said the bearings should reduce the building's shaking and allow greater flexibility in its design. They will be put into a shallow basement beneath the ground floor.
"The isolation bearings are being manufactured in New Zealand. This is the first time bearings of this type have been used here although they are used extensively overseas.
"They're a much simpler type of bearing and consist of sliding puck housed between curved top and bottom plates. The plates are lined with stainless steel and the top and bottom surfaces of the puck are lined with a material that has well-established and durable friction properties."
Wilby said the bearings could move up to 400 millimetres in a severe earthquake.
He said the top and bottom plates of the bearings were cast in Thames, with the stainless steel liners pressed into shape in Christchurch and bonded to the plates.
"New Zealand initiated modern base isolation with the invention of the lead rubber bearing in the 1970s.
"Other countries followed us but also branched out and investigated other types of bearings, whereas New Zealand stuck to the lead rubber bearings."
The Abbotts hope the building, designed by architect Thom Craig, will be finished next year.