Clifton Terraces, for which JG Afrika was appointed as civil and structural engineer, is a 13 storey residential apartment development on Victoria Road in Clifton, Cape Town.
The structure comprises 14 luxury condos, 12 of which are single level, with the upper two each constructed over five storeys. It also has three levels for parking, mechanical and electrical services and storage facilities.
Excavating the huge volume of mountainside earth material in a built-up area to create enough space for the residential levels and the additional three levels of parking that are accessed via Victoria Road was extremely complex.
Traffic had to be carefully controlled to allow the many tipper trucks to access the site to spoil the material. The tower crane also had to be relocated on a number of occasions.
Laterally stabilised using a combination of rock anchors, soil nails and conventional retaining walls, the excavation was shaped to form upper and lower platforms.
Significant attention also had to be given to waterproofing the parking levels. This is considering that groundwater flow paths were interrupted in the new excavation.
The excavation was undertaken at a 60° angle on the north and south sides of the property. Raking columns were, therefore, designed to transfer the building loads to the narrow lower basement of the structure.
Another standout feature of the design is the slender concrete slabs that accommodate the large-span cantilevered balconies.
The building was designed to be earthquake resistant. Engineers also had to consider the differential temperature effects which vary throughout each day. This is in addition to the corrosive effect of salt in the air considering that the structure is located within 100 m of the sea.
Our structures division is proud of its extensive involvement in high-end residential property developments in Cape Town, as well as its participation in industrial, commercial and retail, buildings throughout South Africa.