- Project plans
- Project activities
- Legislation and standards
- Industry context
- Specialist wikis
Last edited 21 Dec 2020
Soil compaction is the removal of pore spaces within soil structures and drainage channels between soil structures. This inhibits root penetration and the movement of air and water in soil. Ref The HS2 London-West Midlands Environmental Statement, Glossary of terms and list of abbreviations, DETR 2013.
Intentional 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 effective compaction to take place, there must be a mixture of particle sizes so that smaller particles can fill the voids between larger particles. Soils with smooth, spherical particles are easier to compact than soils with irregular particles, although their load-bearing capacity can be lower.
Soils are typically categorised as cohesive soils, granular soils or mixed soils. Cohesive soils can be compacted effectively by impact, such as by rammers or sheepsfoot rollers (tamping rollers). Granular soils can be compacted effectively by vibratory plates and smooth-drum vibratory rollers.
The use of vibrating or oscillating rollers is sometimes referred to as dynamic compaction.
See also: Vibro-compaction.
 Related articles on Designing Buildings Wiki
- Bearing capacity.
- Geophysical survey.
- Geotechnical engineering.
- Ground conditions.
- Ground heave.
- Ground improvement techniques.
- Ground investigation.
- Ground investigation.
- Insitu testing of soils.
- Made ground.
- Soil report.
- Trial pit.
- Types of plant.
- Types of soil.
Featured articles and news
LETI publishes guidance for energy efficient home retrofits.
Predictions about adequate post-pandemic IAQ in non-domestic buildings.
Government publishes plans to 'build back greener'.
The contentious nature of claims associated with cladding, fire safety and EWS1 forms.
ECA comments on low-carbon heating systems initiative and Heat and Buildings Strategy.
Cinders and other forms of domestic rubbish created filth but also generated great wealth.
CIC 2050 Group requests input to find out priorities for future industry leaders.
IHBC publishes response to consultation.
Institute applauds funding initiatives but presses for additional retrofit and tax measures.