DHARM46 GEOTECHNICAL ENGINEERING
Information with regard to important I.S. Sieves in common use is given in Table 3.3.
Table 3.3 Certain I.S. Sieves and their aperture sizesDesignation Aperture mm Designation Aperture mm50 mm 50.0 600–μ (60)** 0.600
40 mm 40.0 *500–μ 0.500
425–μ 0.425
20 mm 20.0 *355–μ 0.355
300–μ (30)** 0.300
10 mm 10.0 250–μ 0.250
*5.6 mm 5.6 *180–μ 0.180
150–μ (15)** 0.150
*4.0 mm 4.0 *125–μ 0.125
*2.8 mm 2.8 *90–μ 0.090
240** 2.36
*2.0 mm 2.0 75–μ (8)** 0.075
*1.4 mm 1.4 *63–μ 0.063
120** 1.18
*1.0 mm 1.0 *45–μ 0.045*Proposed as an International Standard (ISO). μ = micron = 0.001 mm.
*Old I.S. Designations were based on nearest one-hundredths of a mm.
The test procedure for sieve analysis has been standardised by ISI as given in IS:2720
(Part IV)–1985.
The general procedure may be summerised as follows:
A series of sieves having different-size openings are stacked with the larger sizes over
the smaller. A receiver is kept at the bottom and a cover is kept at the top of the assembly. The
soil sample to be tested is dried, clumps are broken if necessary, and the sample is passed
through the series of sieves by shaking. The fractions retained on and passing 2 mm IS Sieve
are tested separately. An automatic sieve-shaker, run by an electric motor, may be used; about
10 to 15 minutes of shaking is considered adequate. Larger particles are caught on the upper
sieves, while the smaller ones filter through to be caught on one of the smaller underlying
sieves.
The material retained on any particular sieve should naturally include that retained on
the sieves on top of it, since the sieves are arranged with the aperture size decreasing from top
to bottom. The weight of material retained on each sieve is converted to a percentage of the
*The sieves may be 600-micron, 212-micron and 75-micron I.S. Sieves. These correspond to the
limits of coarse, medium and fine sand. Other sieves may be introduced depending upon the additional
information desired to be obtained from the analysis.