Behind Fortitude Valley train station, two concrete corporate towers face a plaza known as Green Square. A timber and steel canopy connects the buildings, providing shade and shelter to commuters as well as contrast to the stretch of concrete and tiles. The structure is a series of steel frames sandwiched between red recycled hardwood and in this case, the timber serves as decoration only. Plenty of neat bolted connections and inventive concrete mouldings show off the detailing in this plaza project.
The decorative hardwood sections are 200mm deep and bolted to each side of 150×75 galvanised RHS’s (rectangular hollow sections). The frames are evenly spaced. However, some extra frames are staggered are between these, and these require only steel plates, as the RHS frames can do all the work.
The RHS steel portal frame is fully welded at the ‘knee’ to provide lateral stiffness and robustness. The timber is simply bolted to the steel and broken at the knee, showing it is decorative and does not work structurally with the portal frame.
Connection detail: a steel bracket bolted to concrete wall at the end of the walkway.
An extra staggered frame between the regular RHS frames. The extra frames only require a sandwiched steel plate, which are much less stiff than RHS’s.
The entrance canopy
The entrance canopy is framed with 150 UB (150mm deep Universal Beam) steel roof beams. These beams are shaped like capital ‘I’s’ and in this case, the bottom flange is clad with timber. This serves the double function of aesthetic appeal as well as an easy material for the battens to screw into.
A concrete wall decorated with vertical grooves.
The grooves were created by nailing chamfer strips to the plywood formwork. A simple yet effective way of giving texture to a smooth concrete column.
Photography by Jennifer Burley (copyright)