The highlight of the structural steel industry calendar, the 35th Annual Steel Awards hosted by the Southern African Institute of Steel Construction in partnership with BSi Steel, took place on 15 September 2016 in Johannesburg, Cape Town and KwaZulu-Natal concurrently. Attended by over 1000 people the event showcased projects completed in the previous year that demonstrated excellence in the use of structural steel. Sponsors for the event were: Main – Bsi Steel, Popular Vote Feature – Macsteel, Photo competition – Cadex Systems SA, Tubular category – The Association of Steel Tube and Pipe Manufacturers, Light steel frame category – Saint-Gobain, Metal Cladding Category – Global Roofing Solutions, Factory and Warehouse category: Safintra, Partner Sponsors – ArcelorMIttal SA, Genrec Engineering, NJR Steel and Aveng Steel.
The event culminated in the announcement of the overall winner for 2016, the Eastgate Phase 2 Redevelopment, submitted by Tass Engineering – Steelwork Contractors and project team members. In addition to being the overall winner, this project also won the Commercial Architectural Category.
The Eastgate Phase 2 Redevelopment encompasses a number of new structures to give the centre a major facelift. The primary change is the relocation of the lower level cinema complex onto a section of the roof-level car park, enabling more retail space at the lower level plus incorporating substantial additional retail space within the new cinema complex at roof level.
When asked about Eastgate Redevelopment Phase 2 project, Spencer Erling, retired SAISC Director and seasoned Steel Awards judge convener remarked: “I’ve sent students there. I’ve seen the drawings. I just think that what they’ve achieved in a working shopping centre, that’s absolutely changed the mall totally, is really a fantastic piece of engineering work.”
What makes this entry special?
What is special about this project goes hand in hand with why steelwork was chosen as the main structural component in its design. Building a major 5000m2 structure such as this one on a suspended concrete carpark slab over two levels of retail space and keeping the entire shopping centre operational in the process is no mean feat both from a design and a construction point of view.
Underpinning of the foundations was undertaken by mining under the existing lower level suspended slabs firstly by excavating using remote controlled Bobcats with their hoods cut off and then installing mini precast piles.
Special considerations such as the design process, fabrication, transport and erection
Special consideration had to be given to access to the workface for the installation of most of the steelwork. The loading limitation on the rooftop carpark slab was only 2,0kPa with the maximum vehicle weight limited to 5,000 kg’s. The tower crane that was installed by the main contractor on the site covered only 60% of the rooftop cinema complex area and had limited load capacity at radius. A number of the internal structures were designed with plate web girders spanning in excess of fifteen metres which had to be manhandled into position and hoisted by scaffold tower and chain blocks.
Loads of up to 3,5 ton and lengths of over 18,0 metres had to be trolleyed / man handled through and around the cinema structure to then be hoisted to final level by building high scaffold towers over them and pulling them up with suitable capacity chain blocks. An extremely time consuming and expensive means of erection.
Connection design, particularly between the numerous beams throughout the lower levels of the cinema complex and all the Bond-Dek slab support beams was a major cost saving item from a fabrication point of view. Minimal if any welding was employed rather opting for bolted connections with back to back angles bolted through the incoming beam webs to achieve all end plate connection details.
Due to the high visibility of the building, great care was given to the aesthetics. The building form consisted of scalloped segments with sloped Kingspan side cladding and aluminium roof sheeting.
The Project Team
Client / Owner / Developer: Liberty Life
Architect: Batley & Partners
Structural Engineer: Aurecon Group
Quantity Surveyor: NWS Quantity Surveyors
Project Manager: Focus Project Management
Main Contractor: Stefanutti Stocks Building Gauteng
Steelwork Contractor and Nominator: Tass Engineering (Pty) Ltd
Structural Steel Detailer / Detailing Company: 3DStruct
Erector: On Par Erection Works
Metal Roofing and Bond-Dek Supplier: Global Roofing Solutions
Bond-Dek & Shear Stud Installation: Builcon
Roofing and Cladding Contractor: Chartwell Roofing