Utilising deep compaction techniques can, given the right ground conditions, be both a fast and cost-effective way to densify soils at depth.
The depth of influence is dependent on the technique utilised and the nature of soils being treated but generally all deep impact compaction techniques work best for more granular ground conditions.
If a site is deemed suited to dynamically densifying the soil, the decision regarding the method adopted will depend primarily on the desired depth of treatment. Generally this is determined by the loadings, dimensions and the sensitivity of the proposed development.
We have been involved with many sites over the years that have benefited from deep impact compaction. Below is a brief overview of the techniques that we offer.
This process is often referred to as high energy impact compaction (HEIC) or rolling dynamic compaction (RDC).
By using a self-propelled or tractor towed impact, non-smooth drummed roller the soil is densified with the impact of the lifting and falling motion of the non-circular rotating roller (mass). The rotation of the mass at their highest point results in an effective potential energy build up and further rotation of these masses results in the conversion of this potential energy into a falling kinetic energy. The amount of energy transferred is closely related to the amount of potential energy generated in the lifting process. Impact compaction is thus a process of transferring impact loads similar to these found in dynamic compaction, on a continuous basis.
Depths of influence are dependent on the rollers utilised and the nature of the ground being treated but will typically be up to 5m. Typically, the rollers are 3, 4 or 5 sided and are of varying weights.
Rapid impact compaction (RIC) is a ground improvement technique used to densify loose granular soils, using a hydraulic hammer, which repeatedly strikes an impact plate directly to the ground surface at a predetermined grid spacing and blow count. This is dictated by the depth and thickness of the compressible layers.
The energy is transferred to the ground by direct impact at the surface, but also by transmission of dynamic “shock” waves travelling in the ground.
Again, compaction results are highly dependent on soil conditions but typically will achieve effective compaction to depths of up to 7m. This technique if most effective for granular materials containing less than 15% fines.
Dynamic compaction (DC) involves the controlled impact of a crane hoisted weight, falling in a pre-determined grid pattern to improve loose, granular soils and fills.
Dependant on the ground conditions, treatment depths of up to 10m are achievable with this technique.
Get in touch today, and our team will be able to advise you on the best option and package for your construction project.