Once known as the Sydney Football Stadium, Aussie Stadium is a behemoth of white metal and curving iron located on Moore Park Road in Southern Paddington. It is the home ground of both the Sydney Roosters and the South Sydney Rabbitohs, and can be seen best from the top of Oatley Road, just outside the Paddington Town Hall.
structural engineer Ove Arup and Partners
function Football stadium .
geometry span 30m
plan shape circular
building form ?
building aggregate single unit .
structural structure type tensile suspension system
structure material steel
structure shape rectilinear
Design requirements
A football stadium for Sydney became a requirement since the shape and over use of the existing cricket stadium was not compatible with football matches. The plan of the stadium is circular, with seating surrounding a rectangular field. As part of the brief, it was determined that a roof which shelters 60% of the 40 000 spectators was needed and maintains sightlines to the field. Flood lighting must be considered for evening matches.
The structure
Alternatives
Three structures were considered for the roof.
Cantilevered beams or trusses;
Rafter beams supported by a tensile system;
A cable net.
The second was selected for the dramatic roof form, economics and the ability to meet the deadline of construction.
Solution
Designed as a continuous form, a "saddle form" steel roof surmounts a concrete and steel seating bowl. The roof is divided into structural bays that are 8.5m wide, with a tensile suspension system alternating every second bay for the bigger spans.
Vertical load resisting system. The primary roof structure is a series of rafter beams supported by a tensile suspension system that's propped by a concrete filled steel columns. To cater for the mis-alignments of the rafters due to the radial plan. The suspension system supports the larger spans, transferring loads axially, while the simple cantilevers support the smaller spans. The roof is clad with metal sheeting. Pre-cast seating units are supported on steel raking beams which are tied into the concrete frame of the levels below.
Lateral load resisting system. Cross bracing located between rafters resisting horizontal loads axially in the roof structure.
Footings and foundations. Foundations to the building are of Hawkesbury sandstone, which fall away to sand at the western corner. The western corner uses Hercules pre-cast concrete piles, with frankipiles used in other areas.
Design decisions
The site on Sydney's urban edge and adjacent to Sydney's other amphitheater buildings provided a great architectural challenge. Inspiration from the colosseum and surrounding amphitheatre buildings gave rise to its circular plan. Harmonizing with the low-scale residential areas to the north and providing maximum seating at the halfway line created an undulating ribbon-like roof shelter, heightened by the use of two different roof structures. The result is a powerful expression of structure which is a key identifier of the building.
References
Ove Arup partnership, London, England.
The Arup Journal, Spring 1989 Volume 24 Number 1, Ove Arup Partnership, pp. 10.