Rigid Inclusion or Controlled Stiffness Columns (CSC) can be installed through compressible soils to reduce settlement and increase bearing capacity. This technology economically combines the advantage of piles and shallow foundations. Loads are transferred through the high modulus concrete columns to a firm underlying layer. Based on the initial compressibility of the soil the distance between the rigid inclusion reinforcement elements is adapted depending on the allowable settlement of the structure.

This technique can be applied in all construction sectors, for houses, industrial and commercial buildings, embankments and under warehouse slabs, in the latter allowing the use of shallow foundations. Franki Africa offers rigid inclusion using the displacement auger or vibrated tube methods, either as part of a design and build package or as construct only to others’ design.

Positive Features

  • Fast and economical process
  • Slabs in combination with load transfer layers can be designed as standard shallow foundations
  • Noise and vibration level are low
  • Can be carried out to depth of more than 40m
  • Suited to a wide range of soil profiles with a high water table


Applications of Rigid Inclusions

  • Suitable for very weak, cohesive and organic soils.
  • Settlements can be reduced by a factor 8 to 10 under high loads