Subsoil Investigation

For structures to be placed within a proposed area, it is necessary to ascertain the bearing capacity of the soil. This is important for reasons of overestimation and underestimation. Subsoil investigation is a very important aspect of engineering which deals mostly with the subsoil on which foundations for structures will be placed. This in our opinion is an area which must be taken seriously and addressed with expertise.

These aspects are treated under this arm of our company.

A site proposed for development may appear simple and uniform to the eye, but may actually vary and be problematic. The tests we carry out under this arm will confirm the proper status of the site and shed light on aspects such as the types of subsoil layers, the thickness of such subsoil strata, soil geotechnical and foundation properties, groundwater level and so on.

This information would aid in economically maximizing the use of the site.

Under the subsoil investigation we carry out

  • Reconnaissance survey: This entails a preliminary site visit to observe the site situation such as size, which would determine the number and type of tests to be carried out, the general conditions within the area, accessibility, topography, previous site history, e.t.c
  • All or some of the field tests may be carried out, depending on the intended structures, area and size. These may involve
  • Field work , under which the following are executed
    • Trial Pits
    • Hand Augers
    • Borehole Drilling
    • Penetrometer Tests
    • Field Shear Vane tests
  • Laboratory Work: the representative samples obtained from the site during the field work are tested in the laboratory. Laboratory work is carried out to BS 1377 specifications with results presented in tables and graphs included in the report. They usually include;
    • Visual description of samples
    • Strength tests
    • Deformation tests
    • Compaction tests
    • Classification tests to determine the moisture content, particle size distribution, atterberg liquid and plastic limits
    • Chemical tests
  • The Foundation Engineering report is compiled from results obtained from the above and will give a detailed description of
    • The general site details, including location, state of site, geology of the general area, etc
    • Type(s) of soil materials and layers/zones encountered in the course of the investigations and also in relation to the laboratory work carried out
    • Strength and characteristics of soil
    • Depth to water level
    • The foundation design and construction recommendations, with various economic solutions and options concerning shallow foundations as well as deep foundations if found necessary. The foundation depths are also supplied