Fig. 1: Balance
The balance to be used must be sensitive to the extent of 0.1% of total weight of sample taken.
Dry and Wet Sieve Analysis is carried out to quantitatively
determine the Particle/Grain Size Distribution for soil particles
of size 75 micron and bigger. For soil particles of size 4.75mm
and bigger, dry sieve analysis is done and for soil particles of
size above 75 micron and below 4.75mm, wet sieve analysis is also
needed if the soil particles are coated by clay/silt.
The balance to be used must be sensitive to the extent of 0.1% of total weight of sample taken.
I.S sieves (100 mm, 75 mm, 19 mm, 4.75 mm, 2.00 mm, 0.425 mm and 0.075 mm). I.S 460-1962 to be referred. The sieves set should have lid at top and Pan at base.
Mechanical Sieve Shaker
Thermostatically Controlled Hot Air Oven to maintain Temperature between 105 to 110^{O}C.
Two or more large metal or plastic water tight trays or a bucket about 30 cm in diameter and 30 cm deep (sizes of the trays are in the range of 45 to 90 cm^{2} and 8 to 15cm deep).
IS-2720 (Part 4):1985 (Reaffirmed- May 2015) “Methods of test for soils: Grain size analysis".
Maximum size of material present in substantial quantities | Weight to be taken for test |
---|---|
75 mm | 60 kg |
40 mm | 25 kg |
25 mm | 13 kg |
19 mm | 6.5 kg |
12.5 mm | 3.5 kg |
10 mm | 1.5 kg |
6.5 mm | 0.75 kg |
4.75 mm | 0.40 kg |
Table 1: Quantity of sample taken for Test
IS Sieve Designation | 450 mm Dia. Sieves (in kg) | 300 mm Dia. Sieves (in kg) |
---|---|---|
80 mm | 15 kg | 6 kg |
20 mm | 4 kg | 2 kg |
4.75 mm | 1.0 kg | 0.5 kg |
2 mm | -- | 0.20 |
425 micron | -- | 0.050 |
75 micron | -- | 0.025 |
Table 2: Maximum Weight Retained on Sieves
I.S Sieve Number/Size (mm) | Wt. retained in each Sieve (gm) | Percentage retained on each sieve | Cumulative percentage retained on each Sieve | % Finer |
---|---|---|---|---|
100 | ||||
75 | ||||
19 | ||||
4.75 | ||||
2.00 | ||||
0.425 | ||||
0.075 | ||||
PAN |
Table 3
In the case of clayey soils, dry sieving shall not be used and wet sieving shall be used.
Fig. 7 : Plot of Percent Finer vs. Particle Diameter
Fig. 8 : General nature of grain-size distribution of well graded, poorly graded and gap graded soil
Fig. 9 : Soil Classification based on percent finer vs. grain size