The project area is situated within the Cape Flats region, between Nyanga and Mitchells Plain, approximately 25 km from Cape Town’s CBD.
The investigation identified fill and transported dune sands extending to depths of at least 8 metres. The subsurface generally comprised medium-dense, poorly graded sands and silty sands, with interbedded calcrete horizons and hardpan calcrete lenses. Groundwater was encountered at shallow depths ranging from approximately 0.5 to 1.9 metres below ground level.
The findings provided the geotechnical information required to assess excavation stability, groundwater conditions, soil corrosivity and suitable construction methods for the proposed sewer pipeline. The investigation also supported the evaluation of open-trench, pipe-jacking, micro-tunnelling and laterally supported excavation solutions.