Innovative structural steel engineering was recognised at the 2016 Southern African Institute of Steel Construction (SAISC) Steel Awards with Eastgate Phase 2 Redevelopment
Eastgate Phase 2 Redevelopment was also named the winner of the Commercial Architectural category and Aurecon proudly provided the Structural and civil engineering services for the winning project.
The R500mn redevelopment of Johannesburg's first 'super-regional' shopping centre establishment began in November 2013 and steelwork was completed in March 2016, with final project handover scheduled for December 2016. Standout features from both a design and construction point of view include the construction of the major, roof-level 5000 m2 structure on a suspended concrete slab over two levels of retail space, while keeping the entire shopping centre operational. Another noteworthy feature of the construction process was underpinning the existing foundations by literally ‘mining’ under the lower level suspended slabs and installing small precast piles, which in itself is unusual and a seldom seen technique.
“Due to weight limitations and the need to minimise disturbance to the shopping centre, steel was the only solution for the main structural component. It enabled a major lightweight structure to be built over an existing concrete structure with minimal foundation underpinning and strengthening,” explains Aurecon project director, Mark Axelrod.
The new structures involved 1,525 tonness of steel and are exceptionally complex with over 13000 components in the cinema complex alone. Installation presented some major challenges with loading limitations on the rooftop car park slab and the on-site tower crane having a reach limited to 60 per cent of the rooftop area. Steelwork loads were limited to 3.5 tonnes and had to be manhandled around the site and lifted into position using a scaffold tower and chain blocks.
Fabrication cost saving was achieved by way of innovative connection design, particularly between the numerous beams throughout the lower levels of the cinema complex and all the BOND-DEK slab support beams. The use of specially designed bolted connections rather than welding also resulted in cost saving.
