Base isolation technology from San Francisco forms the foundation of Aurecon’s design for Grand Central (NZ); a highly resilient and premium mixed-use development as part of the Christchurch rebuild.
Following the magnitude 6.3 earthquake in February 2011, many buildings in the Christchurch central business district (CBD) sustained damage and were subsequently demolished. The Hotel Grand Chancellor, which once stood as the tallest accommodation building in Christchurch, was no exception with the building left heavily damaged and on a dramatic lean. Following its deconstruction, the owners sort to recover their investment and committed to redeveloping the site.
With the displacement of its hotel businesses, Aurecon leveraged our strong relationship with the Grand Central’s owner to help them realise new potential options for this key site.
Through early and close engagement with the Christchurch City Council (CCC), Aurecon secured resource consent approval for a mixed-use development. The hotel component of the project was removed to accommodate New Zealand Government agencies as anchor tenants and the building scale reduced to a seven-level office complex.
The redevelopment, now known as Grand Central, needed not only to comply with District Plan requirements but also had to address new, high-performance building criteria including high-level seismic resilience, as well as the owner’s sustainability initiatives.
To achieve this, the Aurecon team travelled to Earthquake Protection Systems in San Francisco to observe real-time testing of seismic isolators. The result was the importation and installation of 61 triple pendulum friction bearings beneath each column at the Grand Central.
The innovative base isolation system provides a high tolerance to shaking forces and allows the building to move up to 660 millimetres during large quake events. The testing of this technology is essential to provide assurance on how the building will behave during an event and, ultimately, certainty to tenants and occupants of a post-event recovery.
“In a larger earthquake as experienced in Christchurch in 2011, there could be localised damage such as non-critical services pipes, but these would be easily repairable and the building would be fully operational after,” explained Sean Gledhill, Aurecon Technical Director.
The base isolation system performance then informed the structural design of the building. This included the design of large office floor plates, circa 3000 square metres, which provide connected and collaborative workspaces via an open central atrium and features a ‘floating’ cantilevered stair.
The design outcome was a state of the art building that not only exemplifies a modern and efficient working environment but, critically, incorporates a base isolation system that affords high levels of safety, damage reduction and certainty to owners, tenants and workers of a post-event recovery.
Grand Central was developed as part of the Christchurch Integrated Government Accommodation Project which aimed to return 1 500 staff members from 13 government agencies back into the heart of Christchurch CBD.
Completed in November 2016, the development was the largest of the four new buildings that brought workers back to the CBD and has proven a central focal point for the city’s recovery.
The project has won the following award for Aurecon: