Ground improvement techniques
Contents |
[edit] Introduction
There are a number of ground improvement or ground modification techniques that can be used to stabilise or improve the condition of an area of ground before construction work takes place. This may be necessary to improve or modify the ground shear strength, stiffness, permeability, and so on.
Some of the most techniques include:
[edit] Grouting
Grouting in civil engineering refers to the injection of pumpable materials into a soil or rock formation to change its physical characteristics. It is one of the ways in which ground water can be controlled during civil engineering works. Grouting is suitable where soil permeability would create a heavy demand on pumping or where ground conditions mean it may be economically inefficient to bore wells.
Jet grouting uses high velocity fluid jets to construct cemented soil and is commonly used to underpin foundations and provide excavation support.
Chemical grouting uses a low viscosity, non-particulate grout to permeate pore spaces in granular soils and hardens to create a cemented mass.
For more information, see Grouting in civil engineering.
[edit] Soil mixing
Soil mixing improves soft clays, peats and other weak soils with a high moisture content. It involves mechanically mixing the wet soils with a dry cementitious binder to create soilcrete. This helps increase bearing capacity and decrease settlement.
[edit] Soil compaction
Soil compaction produces an increase in soil density and a decrease in air volume without producing a decrease in water content. It can improve shear strength, stiffness, bearing capacity and stability, reducing settlement and frost heave. This may be necessary in the construction of bases for highways, embankments and so on, or to create a suitable level base for the construction of a building. Existing soil can be compacted, or layers of new soil can be compacted, taking a site to the required level.
For more information see: Soil compaction.
[edit] Vibro-replacement
Vibro-replacement works by using a crane-suspended downhole vibrator to construct stone columns through weak soils, improving their load-bearing and settlement capacities. Another term that can be used for this technique is vibro stone columns (VSC).
For more information, see Vibro-replacement.
[edit] Geotextiles
Geotextiles are typically made using synthetic fibres such as polyester or polypropylene which create a flexible and porous fabric capable of providing strength and stability. Geotextiles have the ability to reinforce, protect, filter, drain and separate, and many applications use them alongside soil, placed at the tension surface for strength purposes.
For more information, see Geotextiles.
[edit] Cement/lime stabilisation
This involves the addition of a binder product such as hydrated lime or quicklime to soil which reduces moisture and improves stability.
[edit] Related articles on Designing Buildings Wiki
Featured articles and news
Registered building inspectors
Building types and conflicts of interest updates explaineed.
Engineering services still struggle with labour shortages
According to latest quarterly services survey of the sector.
Infrastructure that connect the physical and digital domains.
Harnessing robotics and AI in challenging environments
The key to nuclear decommissioning and fusion engineering.
BSRIA announces Lisa Ashworth as new CEO
Tasked with furthering BSRIA’s impressive growth ambitions.
Public buildings get half a million energy efficiency boost
£557 million to switch to cleaner heating and save on energy.
CIOB launches pre-election manifesto
Outlining potential future policies for the next government.
Grenfell Tower Inquiry announcement
Phase 2 hearings come to a close and the final report due in September.
Progress from Parts L, F and O: A whitepaper, one year on.
A replicated study to understand the opinion of practitioners.
ECA announces new president 2024
Electrical engineer and business leader Stuart Smith.
A distinct type of countryside that should be celebrated.
Should Part O be extended to existing buildings?
EAC brands heatwave adaptation a missed opportunity.
Definition of Statutory in workplace and facilities management
Established by IWFM, BESA, CIBSE and BSRIA.
Tackling the transition from traditional heating systems
59% lack the necessary information and confidence to switch.
The general election and the construction industry
As PM, Rishi Sunak announces July 4 date for an election.
Eco apprenticeships continue help grow green workforce
A year after being recognised at the King's coronation.