Ground Improvement Specialists.

Bringing innovative cost-effective ground improvement techniques to the UK.

Controlled Modulus Columns

Controlled Modulus Columns (CMC’s) provide significant advantages over traditional piled foundations. The process developed by Menard in France over 25 years ago is now routinely being used in the UK by many clients as a replacement for precast piles and small diameter rotary bored piles.

The main advantages include:

  • No breaking down of piles, since cropping is done while the concrete is still wet
  • The adoption of a ground bearing foundation and slab, reducing the need for foundations and slabs to be designed to span
  • The rig platform can be incorporated as part of the load mattress below the ground bearing slab, reducing the need for separate piling platforms and load transfer mattresses.
  • No spoil arising’s due to the soil being displaced by our CMC auger, reducing the need to dispose of poor, sometimes contaminated soil.
  • Fully instrumented and semi-automated installation plant providing a fast and quality controlled installation

The CMC technique has already been widely adopted in areas of the UK, where traditional ground improvement techniques, such as stone columns, have been excluded due to the very soft and/or organic soils.  This has allowed structures to be founded on ground bearing foundations, including housing, high bay distribution warehouses, road and rail embankments and tanks.

The method works when an auger is screwed in to soils to the designed depth, which increases the density of the surrounding soil, and as such increases its strength and or bearing capacity. When the auger is extracted a column is developed by pressure grouting, at less than 5 bar, to improve the surrounding soils. The result is a composite ground improvement solution offering enhanced stiffness characteristics, allowing the CMCs and the surrounding soil to share the imposed loadings.  After installation CMCs are installed they are covered by a designed load transfer platform, between 0.4 and 0.8m thick, to efficiently transfer load from the structure to the CMC/Soil matrix.

CMCs were developed by Menard in 1994 and are now used in many countries around the world. Current practice is to install CMCs with a diameter of between 250 and 450mm.

Method

  1. High torque and high static down thrust displaces the soil laterally using the specially designed auger.
  2. During extraction a controlled modulus column is developed by grouting through the hollow stem in the auger.
  3. The result is a 250-450mm diameter composite soil cement column delivering a ground improvement system.
  • Advantages

    • Minimal Spoil
    • High production outputs
    • Suitable for most soil types
    • Can deliver reduced settlements for high loads
    • Densification delivers concrete savings
  • Applications

    • Road & Rail Embankments
    • Storage tanks & port facilities
    • Bridge abutments & retaining walls
    • Warehouse & industrial facilities
Download the Controlled Modulus Columns pdf