Atterbury Group operational company Atterbury Property Holdings’ development of Johannesburg’s Newtown Junction into a mixed-use develop-ment that will comprise a 36 000 m² shopping centre, 30 000 m² of office space, a gymnasium and four levels of basement parking providing 2 400 bays is scheduled for completion in September this year.

Construction on the site started in October 2012, with consulting engineering company Aurecon the structural engineer on the project, providing insight into the complexities of working in the Johannesburg central business district environment as well as marshalling significant project resources at short notice.

“Mixed-use developments often dictate working with a complex design team. On this project, this included three architects who specialise in retail, commercial and heritage. It was essential that Aurecon build strong relationships across these teams, as well as develop efficient construction solutions to expedite the tight programme,” says Aurecon project director and structural engineer Stoffel Mentz.

He adds that the project team for Newtown Junction took particular care in creating a structure that connects the past, present and future with vibrant flair, making it an exciting place for people to work, shop and dine at one of South Africa’s most compelling economic hubs.

Newtown Junction’s retail area includes a portion of steel warehouses (known as the potato sheds) that were originally designed in 1910 for the purpose of storing vegetables and fodder that were distributed to fresh produce markets across the country by rail.

“There are four basement parking levels, two retail levels above the parking [area] as well as three levels dedicated to office space above the retail portion. “A portion of the building was constructed under the elevated M1 highway, which required a unique geometry in order to accommodate the highway piers,” Mentz states.

As s

ome sections of the structure’s roof are only 3 m to 4 m below the structure of the M1 highway above, construction has to be isolated around the highway piers and columns. Moreover, the floor level of the lower retail level is up to 3 m below the founding levels of the highway piers and columns. This meant that Aurecon had to design lateral support systems to protect the bridge piers, ensure that the safety of motorists was not jeopardised as well as design a roofing system that caters for storm water flooding from the highway in these areas.

Besides ongoing changes to the layout of the retail area of the mall, six movie theatres were also incorporated into the project a year before the project’s projected completion.

Aurecon’s project team had to redesign the internal structure of the building to accom-modate these changes and make sure that deadlines were met.

“The specialised theatres required a custom sound insulation solution owing to their proxi- mity to the highway. In order to muffle the sound of the neighbouring traffic, high tech- nology insulation was installed in the theatre areas under the guidance of acoustic experts. We also fast-tracked the design of two of the theatres to ensure that they were fully func-tional when the mall opened,” says Mentz.