The steel structural design has been optimised to efficiently span malls , courts and foodcourts with the minimum of material – thus constituting a saving for the owners , as well as the obvious savings on behalf of the environment .
Landscaping and stormwater planning serve to mitigate the effect of creating a large amount of bulk on the site .
HVAC According to Ian Wingrove of Wingrove Consulting Engineers , the Air Conditioning and Ventilation system installed at Cradlestone Mall makes use of inverter and digital scroll technology to ensure optimum operating and running costs . The tenants have individual control of their air conditioning systems , which allows them to control their operating temperature , times and electrical consumption . The entire HVAC system is installed and designed to comply with the latest SANS 10400 and XA regulations .
STRUCTURAL ENGINEER ’ S REPORT The Cradlestone Mall structure is split into two main elements , a four level 135,000m 2 suspended post-tensioned parking structure adjoining a 90,000m 2 reinforced concrete retail structure .
Challenges of the Site Because of the very steep site , a huge cut-to-fill operation needed to be undertaken to create the final design platform levels which in turn needed to tie into the surrounding road network , which in itself needed to take into account a major future intersection with the N14 highway . The large level difference from one end of the site to the other resulted in a structure that had up to 6 suspended floors .
The founding solution was a combination of large diameter end-bearing piles at the fill platforms and conventional founding at the cut platforms . Platforms were manipulated to best economise the extent of retaining walls , reduce piling quantities to take advantage of the favourable founding conditions , reduce earthworks spoil volumes , maximise natural ventilation etc .
Portions of Retail surface beds in the fill areas were suspended to eliminate the risk of differential settlement . The necessity for delivery truck circulation within the building footprint posed particular structural challenges that needed to be dealt with as economically as possible whilst maintaining the necessary serviceability requirements .
Retail Structure The retail structure comprised mainly of suspended coffer slabs on a mixture of 10m and 8.4m grids . The retail surface beds were specifically designed to be able to carry brickwork in order to save on foundation costs , provide flexibility and speed up the construction program .
A couple of interesting late additions included the introduction of two ‘ floating ’ Pods , one of them suspended 11.5m in the air . These were constructed using a combination of structural steel and reinforced concrete . As usual when cinemas with 12m high walls are constructed on suspended slabs , and in this case over both a trucking tunnel and retail area , they come with interesting design challenges .
Sutherland were particularly proud of the relatively challenging Armadillo roof structure where , by working closely with the architects , they managed to incorporate only minimal primary structural components to achieve relative simplicity and practical buildability .
EAST ELEVATION
Cradlestone Mall 419