APPLICATION OF PROJECT:
Cover over 3 adjacent bowling greens at the Playford City Bowls club, South Australia.
The design, fabrication and installation of the largest tensile membrane canopy structure over a bowling green in the Southern Hemisphere. The 5300m2 PVC (Mehler FR900N) structure covers a total of 21 rinks (120m length), lit with state of the art LED sports lighting, allowing year round utilization of the bowling green’s irrespective of the weather conditions. In addition to bowls, the venue is also used to host corporate and social events.
DESIGN / FABRICATION / INSTALLATION BRIEF
The project was part of a total refurbishment including a new clubhouse and synthetic greens. The bowls club is the fourth largest in SA and the refurbishment has given the club an exciting future.
The design obviously needed to provide a column and obstruction free playing surface, necessitating a large span structure. Structural layouts were optimised based on the best value solution considering installation methodology, fabric design, steel tonnage and foundation size. Parametric design tools were used to run and check multiple structural models and configurations to enable speedy assessment of different options that could be presented to the client for review.
The structure required significant co-ordination with other contractors (builder, greens installer) working on site over the 12-week program. Both steel and fabric deliveries were coordinated using a just-in-time methodology so that items arrived on site as the install crews were ready for them, in the order they were required. This minimised double handling on site and the requirement for excessive laydown and storage areas. The installation occurred in late January and early February when temperatures in Adelaide were extreme – greater than 45 degrees on several days; which necessitated careful planning for fatigue and heat management so that works could be completed safely without compromising productivity.
The installation also involved working with larger fabric panels than is usual for a bowls green cover.
The sawtooth covers form is generated from inclined parallel arches, braced to each other, utilizing valley cables between the arch pairs to provide the fabric with shape and stability. The arches are supported by perimeter columns; the largest loaded area at the arch-column connections has to be carefully stiffened to ensure adequate load transfer while also anchoring the valley cables.
Mehler FR900N – Superior top coating, providing longevity of the fabric structure. The clubs budget was tight and an economical but long lasting material was required. PVC coated polyester membrane was the sensible choice, providing a medium design life with excellent self cleaning properties and a high tensile strength.
All fabrics seams were RF welded, thereby creating ‘structural fabric joints’ to create the large fabric necessary. Closures for the field joints were attached in the factory to reduce the amount of on site work required and to provide a greater degree of confidence in the weatherproofing of the details.
The choice of material meant that weldability of the PVC material was particularly straightforward. Patterning was undertaken to maximise fabric usage and to minimize weld lengths per area; this project was extremely efficient from a fabric usage perspective and the majority of ‘wasted’ material was used for doublers and flashings on the project.
COLLABORATION, CONSTRUCTION AND MAINTENANCE
Installation of the structure was sequenced to allow for civil works to happen in parallel and thereby reduce the overall construction program
Entrant: MakMax Australia
Role played by Entrant: Designer, Engineer, Fabricator, Installer
Location: Elizabeth, SA
Completed: April 2018
Client: Romaldi Constructions Pty Ltd for City of Playford
Architect: TIA Consulting
Engineer: MakMax Australia