ACSE Awards | 2020

Ken Rosewall Arena Redevelopment Sydney Olympic Park

Project Title © Name Introduction • Avoidance of excavation on a contaminated site. The Ken Rosewall Arena at Sydney Olympic Park Excavation for new foundations would not have has received a new lightweight tensile roof structure allowed completion in time due to planning, – converting it into a multi-purpose, all weather remedial works, construction, and disposal facility to attract major sporting and cultural constraints; events. The selection of a self-resolving circular tension structure cleverly utilised the design basis • Geometry developed to achieve a naturally of the original stadium, and allowed a new 100m ventilated space in both Tennis and Netball mode diameter clear spanning roof to be added with no whilst maximising structural efficiency; additional foundations and minimal modification to • Minimise work to the existing bowl and raking the existing bowl structure, maintaining the integrity and beauty of the original Sulman Award-winning structure. The new system utilised the circular design originally purpose-built for the 2000 Sydney form of the structure by creating a self-resolved Olympics. tension structure with new compression rings on the outside and tension rings on the inside – With the requirement to deliver a roof for the similar to a bicycle wheel. These allow for an inaugural ATP cup to be held at the venue in January extremely lightweight structure on a simple radial 2020, Tennis NSW, funded by the NSW Office of grid with 24 cable trusses; Sport, the project was conceived and delivered on an extremely tight timeframe within a 12 month period, • The new roof structure was designed and tuned necessitating a digital, collaborative, and alternative to replace the existing circumferential forces approach to traditional documentation, with all supporting the outside of the existing seating bowl structural works documented and information that achieved the dramatic cantilevering effect. This transferred in digital models between the engineer, shop detailer, fabricator, and contractor. With the in effect “tricked” the existing raker structure that addition of operable walls between bowl and roof, nothing was being changed. The rear of the existing the arena will be used through the autumn, winter, rakers was supported by a circumferential tie in and spring for the Suncorp Super Netball, and other the small perimeter roof. The rakers were jacked sporting and cultural events, finally achieving a to destress and demolish the existing roof and were significant and highly sustainable legacy for venue. “re-lifted” when the new radial cable trusses were prestressed. This retained the nature of the existing Sulman Award winning structure and its legacy Project Brief from Sydney 2000; Arup’s structural team conceived and developed the concept, geometry, design and delivery of the • The roof was raised around the perimeter by 4m canopy roof in collaboration with Cox Architecture in response to Tennis brief and response of the and Fabritecture. Specific structural elements players to “see the sky” for an outdoor event. directly responding to the brief were: The self-resolving roof system allowed this to be achieved with little impact; • Design and delivery in 12 months. • The existing grandstand structure was seamlessly • The simple radial repetitive nature of the roof upgraded to current seismic requirements with construction allowed wire ropes and fabric to simple expressed circumferential bracing added be pre-ordered immediately in December 2019 between existing columns. from initial concept prior to full development of the schematic design; s • The roof structure was form-found by Arup Design & Construction Proces using non-linear dynamic relaxation techniques • The structural design and delivery of cable net roof and all geometry through to delivery controlled of this type and scale is a first in Australia. structurally by the engineer; • The design and delivery throughout was digitally • The design for the new roof structure was delivered from form-finding of geometry, delivered digitally without traditional drawings. surveying and matching new and existing, to Arup provided the roof geometry, preset fabrication and delivery. There were no traditional geometry, and all structural elements and 2D drawings for the new roof. connections digitally to the architect and supply chain in a 3D smart model and directly from • The structural team used advanced application analysis software to Tekla; of digital tools (Rhino, Grasshopper, Geometry Gym and GSA) to complete the structural detailed • The connections were fully designed and design within three months of ordering of cables detailed by Arup in 3D and provided to the to allow maximum time for coordination with shop detailer to complete the fabrication model. the architect – including connection details - The shop detailer worked in Arup’s Sydney fabrication, construction, and event overlay. This office, alongside our team, to streamline this process meant that quality of design and detailing process from design to fabrication – one pass; resolution – such as steelwork connections - was not diminished or sacrificed for time.

2 Ken Rosewall Arena Redevelopment • Wind tunnel testing by simultaneous pressure upgrades – that would not have been achievable if the methods was undertaken in parallel with the radial cables were laid out on the bowl in a traditional design process, and the results integrated into the erection method prior to stressing. digital workflow to streamline the benefits and post- processing. Sustainability • Wire ropes and fabric – long lead time items – ordered from preliminary concept and maintained • This project is an exemplar in regeneration throughout. This included early agreement on and re-purposing an existing asset. All of the central monitor scoreboard weight, sports lighting, existing seating bowl structure and foundations and rigging allowances as Tennis and Netball were retained and re-used with clever high- developed their scopes. quality structural engineering that delivered this whilst fulfilling and exceeding the clients • The design of the cable clamps including the elegant original brief. This venue, under-utilised since crossover detail of the anti-clastic sagging and the end of the Olympics, now has a new more hogging cables was developed from recent Arup functional life without the waste of demolition and testing and project verification reconstruction.. • The structural solution is extremely light in Creativity & Innovation material use, utilising high-strength steel in tension and maximising structural depth beneath Through significant analysis, planning, and use of the limited height plane defined through planning latest techniques in non-linear structural engineering restrictions by crossing over the sagging and design and interoperability, the Arup team hogging cables. This results in a roof that is determined a structural workflow from design and governed by strength and not serviceability/ construction that would ensure project delivery. stiffness with no material wasted. The designs were kept solely within a secure 3D • Sub-framing is minimised by using large fabric environment. Automation and parametric modelling panels, whilst maintaining daylight and obviating hastened design reviews and alterations. The digital the need for artificial lighting during the day. collaboration with designers, architects, contractors and builders supported a comprehensive workflow throughout. The steel detailing was all designed and detailed within the workflow. 3D development of the connection geometry was imported into structural FE analysis, adjusted as needed and exported directly to geometry models and handed to the shop detailer. The development of the cross-over cable clamp detail is a prime example. Steel tubular tension rings were used in lieu of cables to minimise the number of cable clamps. Whilst more complicated to design than wire rope tension rings due to induced flexure under out-off-balance loads, this minimised complexity in design and detailing, and allowed a simple erection method where the inner rings were constructed on towers and cable trusses prefabricated adjacent and lifted in like conventional trusses prior to prestressing. This allowed concurrent works to the bowl – such as seating and balustrade

Ken3 Rosewall Arena Redevelopment • Wind tunnel testing using simultaneous pressure crown to assist in control of wind, rain, and comfort. techniques with site specific wind climate was The structural geometry responds to this, marrying used to minimise and refine the governing structural efficiency with sensible passive climate structural load cases. control. • The structural solution was based on achieving a naturally ventilated and comfortable climate The Challenges and Resolutions within the bowl without active cooling. The 12 Month delivery made possible by: central roof ventilation with operable louvres was intrinsic in the design concept and its elegant • Digital delivery methods used througout the central kingpost and secondary cable structure project. Quality was not sacrificed for time and within the tension rings is light and elegant. this is demonstrated by the quality of the delivered product and elements such as steel connection • Contaminated land was left untouched details – still well considered functionally and aesthetically. Built Environment and Heritage • A structural team that is experienced technically in digital delivery, and open minded in striving for The original Ken Rosewall Arena, designed by new techniques to constantly improve technical BVN in association with BDP (Arup as structural and delivery processes. engineers), was awarded the 2000 Sir John Sulman Medal for Architectural Excellence. This new • The ability of the structural team to clearly addition contributes to the ongoing usefulness, articulate the proposed processes for the client and sustainability, and legacy of the venue for the public delivery team to understand the benefits. without altering its structural form. • Pre-ordering of long lead time elements such as For Tennis NSW and its spectators, the closed-in wire rope and fabric and management of design to arena needed to evoke the sense of being an outdoor this initial order. venue. A translucent PTFE fabric allows controlled natural light into the indoor venue, lighting the • Engagement from the beginning with Fabritecture internal space. The four-metre perimeter doors can – the roof sub-contractor responsible for delivery open to reveal the sky line – visible from centre and erection of the structural steel and D&C court and the stands, reinforcing the sensation of delivery of the fabric. being in an open-roofed venue. • Arup’s existing working relationship with Cox and When the roof-top doors are closed, the arena is Fabritecture and in particular the trust between transformed into a comfortable, world-class venue the parties enabled sound design and delivery suitable for Netball NSW’s professional lines, NSW decisions to be made early in the project - when Swifts and GIANTS Netball, who will call the this is required to ensure a successful outcome. arena home from 2020. It also will see the venue • Client trust in the team. attract new events and the best international talent to Sydney. • Open engagement with the managing contractor, AW Edwards. In both modes the building remains naturally ventilated, with operable openings at the eaves and

4 Ken Rosewall Arena Redevelopment Understanding the Existing Structural Form and connecting elements between new and old where its Construction necessary to accommodate the resultant difference. Detailed condition surveys were undertaken of the Structural Fire Engineering existing structural steel, insitu, and precast concrete structures. The change from open arena to semi-enclosed and enclosed venue was a significant alteration to the Understanding of the structural behaviour of the building category and associated fire hazard under existing building and its initial prestressed state the NCC. The original stadium was fire engineered allowed us to design and deliver with a well planned to omit passive fire protection, and significant construction sequence to protect the existing bowl. structural fire engineering was required to demonstrate compliance under a new fire engineered Existing Structure Position solution, supporting the omission of any passive fire The new roof structure was a pure circle fabricated protection measures. The circular form and double in 24 equal bays. The as-constructed position of the perimeter compression ring naturally provided existing structure was accommodated through a 3D redundancy to the raker supporting columns from survey of the existing and rotating it to best fit the fire exposure in the concourse area. new structure. Spherical bearings were used in the

Ken5 Rosewall Arena Redevelopment