Set to become the largest pool complex constructed in Sydney since the 2000 OlympicsGunyama Park Aquatic and Recreation Centre is a new public community space. Inspired by the beach pools of Sydney, the aquatic centre derives organic curvilinear forms for the outdoor pools, amenities and surrounding landscape. This is juxtaposed by the large 'floating' rectangular form containing the internal pool and gym which references the industrial nature of the site prior to its development. The facility will feature 50m and 25m pools, hydrotherapy and leisure pools, a gym, café, outdoor sports field and running track.
Unique to the project are 50m long steel trusses either side of the pool hall which support 36m long glulam mass timber beams. These beams are the longest free-spanning mass timber beams in Australia. Pressurised ETFE 'pillows' form a translucent roofing membrane between glulam beams. Below the 50m steel truss hangs an architecturally exposed concrete slab and external green roofs are supported on curvilinear concrete slabs.
A key engineering challenge was to create an easily constructible structure for the large-span pool hall to reduce construction risk to the client while still maintaining the architectural vision of a floating structure with an exposed concrete soffit. TTW developed a steel truss design to hang a concrete slab, with structural steel mullions providing vertical support along the 50m long truss. Important to maintaining the architectural vision was refining these mullions to appear as slender as possible, which involved unique structural pin connection details to ensure no bending was created in the structural mullions.
Gunyama showcases innovation with the use of pressurised ETFE pillows which form the structural membrane for the roof, while still allowing natural light to pass through into the pool hall. Glulam beams have been used in a composite section with a CLT top panel to form a U-section which results in a more efficient structure over the large spans.