Ground Improvement & Piling – Definitions & FAQs
What is Soil Modification / Stabilisation?
Soil Modification / Stabilisation involves the addition of product to enhance the physical properties of soils to deem materials suitable for compaction / site reuse. The process can increase the shear strength of a soil and/or control the shrink-swell properties, thus improving the load bearing capacity of a sub-grade to support pavements and foundations.
What is Lime Modification / Stabilisation?
Lime Modification / Stabilisation utilises quicklime to enhance the physical properties of cohesive soils.
What is Cement Modification / Stabilisation?
Cement Modification / Stabilisation utilises cement to enhance the physical properties of granular soils. Cement can also be used to strengthen materials pre-treated with lime and is required if soils will be utilised within the frost susceptible zone as it provides non-frost susceptibility.
What is Deep Soil Mixing?
Deep soil mixing allows soils to be modified in-situ and therefore avoids the requirement for significant deep excavations. The process increases allowable bearing pressure, controls settlement and reduces soil permeability.
What is Mass Soil Mixing?
Mass soil mixing involves the injection of a wet cementitious grout under medium pressure to thoroughly mix soils in-situ utilising an excavator and a specially designed mixing arm to create entire blocks of improved soils to depths of up to five metres.
What are Soil Mixed Columns?
A wet cementitious grout is injected into the ground in columns up to depths of 25 metres. The spacing and width of the columns can vary dependent on the end specification. A transfer mattress is required so it often works hand in hand with mass mixing or traditional stabilisation / modification. The transfer mattress can also provide a very effective media to support services and drainage runs.
What is TurboJet Deep Soil Mixing (DSM)?
TurboJet DSM is a combination of mechanical mixing and jet grouting technology. The process allows the grout to be injected a much higher speed than purely mechanical mixing, which speeds up the process vastly.
Piling is a vertical, structural, deep foundation solution that is driven or drilled into the ground.
What is CFA Piling?
Continuous Flight Auger (CFA) Piling is a cast in-situ process that works very well in soft ground where deep casings or use of drilling support fluids might otherwise be needed. It is fast, low vibration and very economical technique. It is also the quietest form of piling so it is perfect for built up areas.
What is Rotary Bore Piling?
Rotary Bored piles used to support greater loads and are often larger diameter than conventional CFA piles. They can be used to overcome underground obstructions and to penetrate ground too hard to bore using CFA.
What is Contiguous Piling/Secant Piling?
Continguous Piling/Secant Piling are bored piles that are closely spaced (contiguous) to form a retaining wall. This may be for the construction of a deep basement or a cut and cover tunnel.