Index Properties and Key Parameter of Soil - Civil Engineering

Index Properties and Parameters of Soil 

DEFINITIONS OF BASIC KEY TERMS OF SOIL

Index Properties of Soil  

Water Content

Water content (w) is the ratio of the weight of water to the weight of solids.often expressed as a percentage

Index Properties of Soil 

Void Ratio

Void ratio (e) is the ratio of the volume of void spaces to the volume of solids.The void ratio is usually expressed as a decimal quantity.
 

Index Properties of Soil

 Porosity

Porosity (n) is the ratio of the volume of voids to the total volume of soil. 
 

Index Properties of Soil

 Degree of Saturation

Degree of saturation (S) is the ratio of the volume of water to the volume of voids. 
 

Index Properties of Soil

 Bulk Unit weight

Bulk unit weight (γ) is the weight density, that is, the weight of a soil per unit volume. 
 

Index Properties of Soil

 Saturated Unit Weight

Saturated unit weight (γsat) is the weight of a saturated soil per unit volume. 
 

Index Properties of Soil

 Dry Unit Weight

Dry unit weight (γd) is the weight of a dry soil per unit volume. 
 

Index Properties of Soil 

 Effective Unit Weight

 Effective unit weight (γ′) is the weight of a saturated soil submerged in water per unit volume. 

Index Properties of Soil

 Relative Density

Relative density (Dr) is an index that quantifes the degree of packing between the loosest and densest state of coarse-grained soils. 
 

Index Properties of Soil

 Density Index

Density index (Id) is a similar measure (not identical) to relative density. 
 

Index Properties of Soil

 Unit Weight

Unit weight ratio or density ratio (Rd) is the ratio of the unit weight of the soil to that of water. 
 

Index Properties of Soil

 Swell Factor

Swell factor (SF) is the ratio of the volume of excavated material to the volume of in situ material (sometimes called borrow pit material or bank material). 
 

Index Properties of Soil

 Liquid Limit

Liquid limit (LL) is the water content at which a soil changes from a plastic state to a liquid state. 
 

Index Properties of Soil 

 Plastic Limit

Plastic limit (PL) is the water content at which a soil changes from a semisolid to a plastic state. 
 

Index Properties of Soil

 Shrinkage Limit

Shrinkage limit (SL) is the water content at which a soil changes from a solid to a semisolid state without further change in volume. 
 

Index Properties of Soil

 Plasticity Index

Plasticity index (PI) is the range of water content for which a soil will behave as a plastic material (deformation without cracking). 
 

Index Properties of Soil

 Liquidity Index

Liquidity index (LI) is a measure of soil strength using the Atterberg limits (liquid and plastic limits based on test data). 
 

Index Properties of Soil

 Shrinkage Index

Shrinkage index (SI) is the range of water content for which a soil will behave as a semisolid (deformation with cracking).