Many engineering properties of soils are related with the particle size characteristics. The size of particles varies from more than 30 cm to less than 0.001 mm. On the basis of their particle size soils may be classified as gravel, sand, silt or clay. A simple classification based on particle size has been proposed by Massachusetts Institute of Technology (MIT) and is presented below.
U.S Standard Sieve No. | Sieve Opening (mm) |
4 | 4.75 |
10 | 2.00 |
20 | 0.85 |
40 | 0.425 |
60 | 0.25 |
100 | 0.15 |
140 | 0.106 |
200 | 0.075 |