Grain size distribution- Sieve analysis

AIM

Select sieves as per I.S specifications and perform sieving.

Obtain percentage of soil retained on each sieve.

Draw graph between log grain size of soil and % finer.

THEORY

The grain size analysis is widely used in classification of soils. The data obtained from grain size distribution curves is used in the design of filters for earth dams and to determine suitability of soil for road construction, air field etc. Information obtained from grain size analysis can be used to predict soil water movement although permeability tests are more generally used.

Apparatus
Balance, I.S sieves, Rubber pestle and mortar, mechanical Sieve Shaker
The grain size analysis is an attempt to determine the relative proportions of different grain sizes which make up a given soil mass. The balance to be used must be sensitive to the extent of 0.1% of total weight of sample taken.I.S 460-1962 are to used. The sieves for soil tests: 4.75 mm to 75 microns.

PROCEDURE
1.For soil samples of soil retained on 75 micron I.S sieve
(a) The proportion of soil sample retained on 75 micron I.S sieve is weighed and recorded weight of soil sample is as per I.S 2720.
(b) I.S sieves are selected and arranged in the order as shown in the table.
(c) The soil sample is separated into various fractions by sieving through above sieves placed in the above mentioned order.
(d) The weight of soil retained on each sieve is recorded.
(e) The moisture content of soil if above 5% it is to be measured and recorded.
2.No particle of soil sample shall be pushed through the sieves.

OBSERVATIONS AND RECORDING
Weight of soil sample:
Moisture content:

I.S sieve number or size in mm	Wt.Retained in each sieve (gm)	Percentage on each sieve	Cumulative% retained on each sieve	% finer	Remarks
4.75
4.00
3.36
2.40
1.46
1.20
0.60
0.30
0.15
0.075

GRAPH
Draw graph between log sieve size vs % finer. The graph is known as grading curve. Corresponding to 10%, 30% and 60% finer, obtain diameters from graph are designated as D10, D30, D60.

CALCULATION
1. The percentage of soil retained on each sieve shall be calculated on the basis of total weight of soil sample taken.
2. Cumulative percentage of soil retained on successive sieve is found.

Geotechnicial Engineering laboratory test

1. Physical properties of minerals
2. Determination of natural moisture of soil
3. Determination of specific gravity of soil
4. Sand replacement method
5. Sieve analysis-Grain distribution
6. Hydrometer analysis of soil
7. Determination of liquid limit
8. Determination of Plastic limit
9. Determination of Shrinkage limit
10. Direct shear test
11. Proctor test