Introduction: Soil Types and Properties

Question 1

What are the main soil types based on grain size?

Answer 1

1. Rock - Hard or soft; used in construction (e.g., granite, basalt).
2. Gravel - Formed by rivers or surf, highly permeable.
3. Sand - Small particles of stone, good permeability.
4. Silt - Formed by rivers/wind, low permeability, hard underwater.
5. Clay - Highly cohesive, low permeability, used for dikes.
6. Loam - Similar to clay, contains organic matter, used in construction.
7. Peat - Decomposed organic material, highly compressible.

Question 2

What are the key physical properties of soil?

Answer 2

• Density (specific and volumetric)
• Porosity and void ratio
• Moisture content
• Bearing capacity
• Permeability

Question 3

What is permeability?

Answer 3

Permeability is the ability of soil to allow water to pass through it. It depends on the percentage of voids and grain size distribution.

Question 4

Which soil type is the most permeable?

Answer 4

Sand is the most permeable due to its larger grain size and high void ratio, whereas clay has the lowest permeability.