Soil classification in Civil Engineering.

Classification of different types of soil is done by different classification systems which as follows

A) Particle size classification:

1) MIT system (Massachusetts Institute of technology in USA).

2) International classification system

3) U.S. Bureau of soil classification

B) Textural classification

C) AASHTO classification system

D) Unified soil classification system

E) Indian Standard classification system

F) Boundary classification system

G) Field identification of soils

H) General characteristics of soil of different groups.

In Indian Standard classification system following basic soil components have been included as follows:

Soil : Coarse grained components:

Boulder: More than 300mm

Cobble: Less than 300mm

Gravel: Coarse: 80 to 20 mm IS sieve size

Fine: 20 to 4.75mm

Sand: Coarse: 4.75 to 2.0 mm

Medium: 2.0mm to 425 micron

Fine: 425 micron to 65 micron.

Fine grained components:

Silt: Less than 75 micron

Clay: Less than 75 micron

Organic matter: Depends on various sizes and stages of decomposition.