Sieve Analysis

ME 420L/ME 506L: Soil Mechanics Laboratory Lab No. 3: Sieve Analysis ASTM D422

The grain size analysis (sieve analysis) is a method to determine the relative proportions of grain sizes that make up a given soil. The grain size distribution is used for soil classification under the USCS, as well as a number of other practical applications (e.g., estimation of mechanical properties, evaluation of permeability, construction of soil filters among various applications). The test procedure involves shaking the soil through sieves with known opening sizes and weighing the soil retained on each sieve.

Procedure 1. Obtain 500 g of oven-dry representative soil sample (for the largest particle of 4.75 mm). 2. Clean and weigh #4, #10, #20, #40, #60, #140, and #200 sieves and pan to nearest 0.1 g, (Figures 1, 2, and 3). Compare the size of the soil grains to the chosen sieves. Add sieves if necessary.

Figure 1

Figure 2

Figure 3

3. Stack sieves on a pan from No. 200 progressing up to increasing larger sizes. It is desired to have 100% passing for the top sieve; this sieve may be excluded from the stack. Pour the soil in the top sieve. Place cover on top sieve. (Figures 4 and 5)

Figure 4

Figure 5

4. Place the stack in a mechanical shaker. Shake for approximately 10 to 15 minutes (Figure 6).

Note: This lab instruction has been prepared by using the following Soil Mechanics Laboratory Manual: Das, B. M. (2009). Soil Mechanics Laboratory Manual. 7th Edition, Oxford University Press Inc, New York.

ME 420L/ME 506L: Soil Mechanics Laboratory Lab No. 3: Sieve Analysis ASTM D422

Figure 6

5. Weigh the amount of soil retained on each sieve and in the bottom pan.

Calculations 1. Calculate the mass retained, percent retained, and cumulative percent passing the sieves. Check that the sum of the mass of soil retained is close to the mass of the soil with which you started the test (discrepancies may exist due to soil particles retained on the sieves). 2. Plot the cumulative percent passing versus particle size (mm) on a semi-log scale (GSD curve). Determine Cu and Cc. If the percent fines in the soil (sizes passing sieve #200) was in excess of 5%, the LL and PL tests must to also be run (minus #40) in order to classify the soil according to the USCS.

Note Your lab report should include: 1. 2. 3. 4. 5.

A complete description of the soil The relationship between the sieve number and sieve opening Type of the soil based on the GSD curve, Cu, and Cc Sources of errors and the effect of them on grain size distribution Applications of sieve analysis in different engineering fields

Note: This lab instruction has been prepared by using the following Soil Mechanics Laboratory Manual: Das, B. M. (2009). Soil Mechanics Laboratory Manual. 7th Edition, Oxford University Press Inc, New York.