• Desk Study: A review of existing geological and geotechnical information, including historical maps, borehole logs, and previous investigations in the area.   

• Soil Sampling: Collection of soil samples from different depths using techniques like hand auger drilling, test pits, or machine-driven boreholes.
  
   
• Laboratory Testing: Analysis of the collected soil samples to determine their properties, such as grain size distribution, plasticity index, shear strength, and compressibility.
• Report Preparation: A detailed report summarizing the findings of the investigation, including recommendations for foundation design and construction.

Phase 2 Investigation (if required):

• Additional Site Investigations: If necessary, further investigations may be conducted, such as plate load tests or dynamic cone penetration tests, to provide more detailed information about the soil’s bearing capacity and compressibility.
• Foundation Design: Based on the findings of the investigation, geotechnical engineers can provide recommendations for the type of foundation suitable for the site, such as strip footings, raft foundations, or pile foundations. 

Key Considerations for Residential Geotechnical Investigations in South Africa:

• Expansive Soils: Many areas in South Africa have expansive soils that can swell or shrink with changes in moisture content, which can cause significant damage to foundations.   
  
   
• Dolomites: Areas underlain by dolomite formations may be prone to subsidence and sinkholes, requiring careful investigation and design considerations.   
  
   
• Slope Stability: Sloping sites may be susceptible to landslides or erosion, especially during heavy rainfall events.  
  
   
• Seismic Activity: While South Africa is not a high seismic risk area, it’s still important to consider seismic loads in foundation design, particularly in certain regions.

By conducting a thorough geotechnical investigation, it is possible to identify potential geotechnical risks and design appropriate foundation solutions to ensure the long-term stability and safety of commercial infastructures in South Africa.