MULTIPLEX has completed a new tower and retail precinct at 80 Collins St in Melbourne’s CBD for new owners Dexus and the Dexus Wholesale Property Fund.
The development was delivered to completion by QIC GRE, which sold the asset in May last year to Dexus and DWPF for a record $1.47 billion.
Designed by Woods Bagot in collaboration with Dutch firm UN Studio, the precinct comprises a new 38-level office tower providing circa 43,000 sqm of premium office space and a 255-room boutique hotel as well as major refurbishments to the existing 47 level A-grade office building.
Multiplex regional managing director Graham Cottam said 80 Collins St was an extremely complex build, “with the new office tower constructed to cantilever 12 metres over existing buildings on Collins St, the first time this engineering feat has been achieved on such a scale. It is built to withstand 30,000kN tensile force through the concrete core, which is three times that of what has been previously built in Australia.”
Cottam said Multiplex developed an innovative construction method using steel ducts to facilitate the feeding of steel bars and reinforcements to form a new tension bar system. The system effectively withstands and transfers the tensile loads of the cantilevered structure to the building core, without the requirement for additional structural support columns.
Other innovations in the construction include the first use of a double-decker lift system in Australia. Two lift cars stacked on top of each other allow the lift to double its capacity without requiring extra space within the lift core. This allowed 18 lift cars to be operational within nine lift shafts, minimising the size of the lift shaft and maximising NLA for the tower.
Construction commenced in April 2017 with some 800 workers on-site every day in peak periods and approximately 7,000 tonnes of structural steel and 30,000 cubic metres of concrete used throughout construction.
