Cohesive and Non-Cohesive Soil
Cohesive soils contain fine particles that bind together, while non-cohesive soils are made up of looser granular materials such as sand and gravel. The difference affects how soil behaves under load, drains water and responds during construction. Understanding soil type is an important part of geotechnical assessment and site investigation.
What is Non-Cohesive Soil?
Non-cohesive soils, sometimes known as cohesion-less soils, are essentially the opposite of cohesive soils. Due to the type of soil it is, the grain of the soil is unable to hold together, no matter how wet you make it or when you dry it out. Non-cohesive soil is easily affected by environmental conditions such as wind and rain and this type of soil is difficult for use in a range of projects. Some of the most common types of non-cohesive soils are sand and gravel.
What is Non-Cohesive Soil Used For?
Non-cohesive soil is used for a wide range of purposes, especially in supporting things such as foundations. Some of the main uses for non-cohesive soils are:
- Backfill for Retaining Walls
- Drainage Fill
- Fill Slopes
- Foundation Fill
- Embankments
What is Cohesive Soil?
Cohesive soil is when the soil is made up of fine grain and the particles of the soil stick easily together. Cohesive soil has good plasticity, which is when soil can be easily moulded or retain a different shape, this is due to the soil being soft but having high moisture levels, this means that once the soil dries out it will become hard. The moisture levels in the soil allow for shrinkage and expansion and some of the most common types of cohesive soil are silt, clay and peat.
What is Cohesive Soil Used For?
Due to its plasticity cohesive soil is suitable for a wide range of stable uses. Some of the main uses for cohesive soil are:
- Stable Foundations
- Retaining Walls
- Sloped Land
- Load Bearing Land
COHESIVE AND NON-COHESIVE SOIL TESTING
Solmek provides soil testing for cohesive and non-cohesive soils to help assess ground conditions and inform construction and development decisions. Where soil type or behaviour is uncertain, our geotechnical testing can help identify key properties and determine whether further investigation, removal or ground stabilisation may be required.