Page 435 - Water and wastewater engineering
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11-8 WATER AND WASTEWATER ENGINEERING
99.99 99.9 99.5 99 98 95 90 80 70 60 5040 30 20 10 5 2 1 0.5 0.1 0.01
10.0
Sieve size, mm 1.0
0.10
0.01 0.10.2 1 2 5 10 20 3040 5060 70 80 90 95 98 99 99.8 99.9 99.99
Cumulative mass percent passing
FIGURE 11-3
Grain size analysis of run-of-bank sand.
The uniformity coefficient is then
.
085 mm
P 60
U 28 .
.
P 10 0 30 mm
Comments:
1. Obviously, this sand does not fall within the prescribed limits. Although this sand could
be processed to meet the specifications, in the United States the sand would be rejected
and the supplier would be required to provide a replacement.
2. Probability paper is not required to determine E and U. The x -axis scale may be arithme-
tic or any other scale that allows a smooth curve to be drawn through the data so the d 10
and d 60 sizes can be determined.
3. A spreadsheet plot with a curve fitting function is very useful in selecting the plotting
axis and determination of the d 10 and d 60 sizes.
