Sieve Analysis

A sieve analysis shakes a dry sample through a stack of sieves, from coarse at the top to fine at the bottom, and weighs what each one retains. Adding up the retained masses from the top gives the percentage of the sample finer than each sieve, the percent passing. Plotted against the log of the aperture, this is the grading curve. From it come the sizes D₁₀, D₃₀ and D₆₀, which 10%, 30% and 60% of the sample is finer than, and from those the coefficients of uniformity and curvature that describe how well graded the soil is.

What you are seeing

• Mass retained. The mass, in grams, left on each sieve and in the pan. Change any of them to change the sample.
• The grading curve. Percent passing each sieve against its aperture, on a log axis. The pan is counted in the total but has no aperture, so it is not plotted.
• Key results. The total mass, the fines passing 0.075 mm, and the characteristic sizes and coefficients. Each D is interpolated linearly in log size between the two sieves either side of it; a dash means the curve does not reach that percentage.