Factors affecting Soil Permeability
Factors affecting permeability include Particle size, Void ratio, Permeant, Shape of particles, Degree of saturation, soil fabric, Impurities in water and Adsorbed cation on clay mineral surface
What is soil permeability?
Permeability is the ease with which the water can flow through soil. Larger the pores more the permeability and vice versa.
What are the factors affecting soil permeability?
• Particle size
• Effect of void ratio
• Effect of permeant
• Shape of particles
• Degree of saturation
• Effect of soil fabric
• Impurities in water
• Effects of adsorbed cation on clay mineral surface
Permeability Factors explained
Particle size affects permeability. Allen Hazen formula (image below explains it).
Effect of void ratio and permanent is also show in the image below.
• Permeant is the fluid flowing through the soil water.
• With a change in temperature, the unit weight of the water does not change but viscosity changes.
Degree of saturation, Effect of soil fabric and Impurities
Degree of saturation.
• Unsaturated soils would have lesser permeability compared to the saturated soils.
Effect of soil fabric.
• Dispersed soil will have lesser void ratio hence lesser permeability vice versa in case of flocculent structure.
Impurities in water
• Impurities would clog the pores and leads to lesser permeability
Effects of adsorbed cation on clay mineral surface
The order of permeability based on the cation on the surface of montmorillonite.
• K+ < Na+ <H+ <Ca2+
The order of permeability based on the cation on the surface of kaolinite.
• Na+ < K+ <Ca2+ <H