Construction World December 2023

An important point to note is the efficiency of the underpass design and construction method. The pile abutment design and slab-on-ground construction method resulted in a very efficient excavation of the material compared the conventional methods which may require up to 60% more volume removed simply for working space. From outset KMC approached this project with a keen approach to showcase not only the benefits of smarter construction techniques, methods and high-tech equipment but also our ability to deliver a product to a client which boasts a high level of quality at an affordable rate. This is befitting of our vision: to be the Contractor of choice for quality infrastructure – leading through innovation. We deliver our vision through our values. We strive to change lives with high quality infrastructure and to leave a proud legacy for generations to come. 

was able to drill and install 900 mm diameter soldier piles, unhindered. The same process applied to the Westbound carriageway, with 42 piles installed in record time without reducing the vehicle-carrying capacity of the freeway the entire time. Another unique characteristic relating to the construction of this underpass is that it was constructed in reverse i.e., the piles (abutments) were constructed first, thereafter the deck slabs were constructed prior to any excavations occurring. Once these structural elements were completed freeway traffic was able to travel on their respective carriageways while the underpass was excavated safely underneath the deck slabs because the pile-and-slab design acted as a highly stable portal frame. Another on-site improvement which can be attributed to innovative design is the change in base layer from conventional crushed stone base to the BSM layer described above. This layer performs equally well, if not better at times than the conventional alternative. It also allowed for somewhat weaker materials to be reclaimed and suitably improved (strengthened) for use as a high-quality road building material. A crucial area of impact was the watercourse flowing through a section of the site. An Armourflex Channel and Major Culvert were constructed in such a way to manage the flow of water at safe operating levels, even during flood conditions. The floor of the major culvert was built wider than required in order to reduce the need for future disturbance of the water course should a second carriageway be constructed to further widen Hazeldean drive.

• Company entering: KMC Construction • Client: Balwin Properties • Main Contractor: KMC Construction • Principal Agent: Civil Concepts • Consulting Engineer: Superstructures Africa • Subcontractor: Makarios Geodynamics PROJECT INFORMATION

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22 nd Best Projects Awards 2023