While you can never be certain about power and water supply in Gauteng the one thing that is as consistent as night following day is the construction of shopping malls.
The latest to be grabbing column space is the Mall of Africa in Midrand. In true Gauteng style Waterall City, where the mall is located, when complete, will encapsulate the concept of “eat-shop-work-play” in an integrated living environment.
Earthworks for the 130 000 m² Mall of Africa began in October 2012 and its opening is scheduled for April 2016.
Atterbury Property Developers contracted Aurecon to undertake both the civil and structural engineering of the development.
The recent strike in the metals and engineering sector saw over 200 000 Numsa members embark on what was dubbed as an ‘indefinite strike’. This could potentially have derailed a number of major deliverables on this project.
“Detailed design documentation had to be fast-tracked to enable the contractor, the WBHO/Group Five JV, to pre-order rebar and steel formwork ahead of the strike. This mitigated many of the potential delays as a result of the strike,” explains Aurecon project director, Nicol Labuschagne.
Other challenges surrounding the construction programme are of a geotechnical nature.
The underlying geological profile of the 16,5 ha footprint of the mall site comprises soft to very hard rock granites with intrusions of diabase in places. Residual soils have developed from the weathering of the granites and diabase bedrock with overlying transported hillwash of varying depths and an abundance of subsoil groundwater in places.
“Geotechnical challenges to be dealt with as a result included the upfront profiling of the granite bedrock to minimise the amount of hard rock excavations, the subsoil drainage design over such a large footprint, and the varying founding conditions encountered due to the variable nature of the site geology,” says Labuschagne.
“This meant that no single founding solution could be used. Our project teams had to tailor the founding solution for each column or wall in accordance with its specific site condition, making use of either piling or conventional spread footings or a combination of both.”