Clients: Olympic Coordination Authority, Royal Agricultural Society
Architects: Ancher, Mortlock & Wooley – Ken Wooley, Phil Baigent, Steve Thomas
Engineers: Ove Arup & Partners
Contractors: Thiess Contractors

This magnificent timber dome, 97m across and 42m high, together with three linked, open-plan timber halls, forms a complex known as the Sydney Showground Exhibition Buildings. Covering a total area of 14,400m2, this is one of the largest of the award winning structures constructed for the 2000 Olympic Games. Since then, it has provided permanent facilities for the Royal Agricultural Society - an example of successful ‘Games Legacy’ planning.

The Olympic Exhibition Centre has two main sections, the dome itself, and a flexibly planned series of rectangular halls, with a total capacity of 18,000.

As the Sydney Olympics were identified at the early planning stages as the ‘Green Games’, the Olympic Coordination Authority pursued sustainable development principles. In particular, they looked for the conservation of indigenous species and natural resources, and careful pollution control. As a result it was decided at the concept design stage that timber should be used, both for the main structural elements and also for the greater part of the finishes. It was recognised that timber is a renewable building material with low embodied energy when compared with the alternatives. The Exhibition Buildings were thus designed and constructed using mainly glulam, for its unique aesthetics, cost-effectiveness and environmental credentials.

During the Olympics, the Exhibition Halls hosted events such as volleyball, handball, badminton and rhythmic gymnastics. Paralympics sports included basketball, handball and volleyball.

Energy-efficient air conditioning was specified, using an innovative displacement system, in which air, conditioned from a radiant cooling slab, is introduced at low velocity through a perimeter trench, entering by means of diffusers. The air then rises to extractors in the crown.

At the erection stage, advantage was taken of the prefabrication potential of timber to integrate structural assembly with roofing and service installation at ground level. The dome was then jacked into position, working from the centre outwards.

The dome is a relatively conventional geodesic structure, using Radiata pine glulam, sourced from South Australian plantations, for the principal compression members. These delineate the structural form, whilst steelwork has been used for the struts and connections.

All other elements have been scaled and detailed to complement the use of timber. The ribs meet at fabricated steel connection nodes where each timber element has eight couplers for threaded anchor rods. The latter were permanently bonded into the glulam, using epoxy adhesive. To resist the increased loads towards the base, the timber sections progressively increase from 800mm x 30mm in the top circle of the dome to 800mm x 230mm at the base.

The roof form for the rectangular halls was constrained by the partitions. Some distinction was required for each of the six, potentially separate, pavilions. At the same time, their structure needed to be capable of functioning with moveable walls. Also, the aesthetics demanded a roof structure in sympathy with the dome.

The solution was again to use glulam elements, combined with steel struts, to arch down from the roof peak to steel support columns. At the perimeter, the steel and timber elements form a truss in the plane of the roof to receive the horizontal thrust from the arches, resolving the actions through transverse tension members placed on the operable wall support lines.

 

AWARDS

Finalist in Australian Constructors Awards, Award of Merit – Australian Timber Design Awards, 2000
Institution of Structural Engineers (UK) Special Awards, 1999
Association of Consulting Engineers of Australia - Special Merit Award, 1998