Bulk earthworks

Cape Flats WWTW

2021 – 2022
Client : Stefanutti Stocks
Value : R31 M
Scope of works : The scope of works entails the dismantle and removal of pipelines, electricity transmission lines, cables and the demolition and removal of structures/buildings


Bulk and restricted excavations shall be taken down to the underside of the concrete blinding layers for the various structures. After the earthworks operations have been carried out, the surface shall be watered so that the top 300mm is at optimum moisture content, and this layer shall then be compacted to 100% Mod AASHTO density. The subgrade shall then be carefully levelled and prepared to receive the concrete blinding.

Soil Improvement

Rapid Impact compaction shall be done before any restricted excavations commence under the Admin building and electrical buildings. The layout and compaction indication is that 35 blows delivered with a 12 tonne weight dropped through a height of 1.5m on a 3.5m x 3.5m grid and one positioned centrally, will provide sufficient energy to compact the upper 4m. After compaction, the area will be uneven and should hence be scarified to a depth of 200mm and compacted to 100% Mod AASHTO density using a smooth drum vibratory roller operating in high-frequency mode. All foundations can then be founded within the compacted soil mass.