Soil compaction
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.
Soil compaction can be purposeful (intentional) or consequential (unintentional) such as settlement that might occur due to vehicle movement.
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.
Excessive compaction can lead to soils breaking down and separating. This can cause compacted layers to weaken.
See also: Vibro-compaction.
[edit] Related articles on Designing Buildings Wiki
- Bearing capacity.
- Excavation.
- Geophysical survey.
- Geotechnical engineering.
- Ground conditions.
- Ground heave.
- Ground improvement techniques.
- Ground investigation.
- Ground investigation.
- Groundworks.
- Insitu testing of soils.
- Made ground.
- Soil report.
- Trial pit.
- Types of plant.
- Types of soil.
- Vibro-compaction.
Featured articles and news
Architects, architecture, buildings, and inspiration in film
The close ties between makers and the movies, with our long list of suggested viewing.
SELECT three-point plan for action issued to MSPs
Call for Scottish regulation, green skills and recognition of electrotechnical industry as part of a manifesto for Scottish Parliamentary elections.
UCEM becomes the University of the Built Environment
Major milestone in its 106-year history, follows recent merger with London School of Architecture (LSE).
Professional practical experience for Architects in training
The long process to transform the nature of education and professional practical experience in the Architecture profession following recent reports.
A people-first approach to retrofit
Moving away from the destructive paradigm of fabric-first.
International Electrician Day, 10 June 2025
Celebrating the role of electrical engineers from André-Marie Amperè, today and for the future.
New guide for clients launched at Houses of Parliament
'There has never been a more important time for clients to step up and ...ask the right questions'
The impact of recycled slate tiles
Innovation across the decades.
EPC changes for existing buildings
Changes and their context as the new RdSAP methodology comes into use from 15 June.
Skills England publishes Sector skills needs assessments
Priority areas relating to the built environment highlighted and described in brief.
BSRIA HVAC Market Watch - May 2025 Edition
Heat Pump Market Outlook: Policy, Performance & Refrigerant Trends for 2025–2028.
Committing to EDI in construction with CIOB
Built Environment professional bodies deepen commitment to EDI with two new signatories: CIAT and CICES.
Government Grenfell progress report at a glance
Line by line recomendation overview, with links to more details.
An engaging and lively review of his professional life.
Sustainable heating for listed buildings
A problem that needs to be approached intelligently.
50th Golden anniversary ECA Edmundson apprentice award
Deadline for entries has been extended to Friday 27 June, so don't miss out!
CIAT at the London Festival of Architecture
Designing for Everyone: Breaking Barriers in Inclusive Architecture.
Mixed reactions to apprenticeship and skills reform 2025
A 'welcome shift' for some and a 'backwards step' for others.