Chapter 2 Origin of Soil and Grain Size

Chapter 2

D60 0.42 D302 0.212
2.1 Cu = = = 2.625 ≈ 2.63 ; Cc = = = 0.656 ≈ 0.66
D10 0.16 ( D60 )( D10 ) (0.42)(0.16)


D60 0.81 D302 0.412
2.2 Cu = = = 3.0 ; Cc = = = 0.768 ≈ 0.77
D10 0.27 ( D60 )( D10 ) (0.81)(0.27)


2.3 a.
Sieve Mass of soil retained Percent retained Percent
no. on each sieve (g) on each sieve finer
4 28 4.54 95.46
10 42 6.81 88.65
20 48 7.78 80.88
40 128 20.75 60.13
60 221 35.82 24.31
100 86 13.94 10.37
200 40 6.48 3.89
Pan 24 3.89 0.00
∑ 617 g




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, b. D10 = 0.16 mm; D30 = 0.29 mm; D60 = 0.45 mm

D60 0.45
c. Cu = = = 2.812 ≈ 2.81
D10 0.16

D302 0.292
d. Cc = = = 1.168 ≈ 1.17
( D60 )( D10 ) (0.45)(0.16)



2.4 a.
Sieve Mass of soil retained Percent retained Percent
no. on each sieve (g) on each sieve Finer
4 0 0.0 100.00
6 30 6.0 94.0
10 48.7 9.74 84.26
20 127.3 25.46 58.80
40 96.8 19.36 39.44
60 76.6 15.32 24.12
100 55.2 11.04 13.08
200 43.4 8.68 4.40
Pan 22 4.40 0.00
∑ 500 g




b. D10 = 0.13 mm; D30 = 0.3 mm; D60 = 0.9 mm

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© 2014 Cengage Learning. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.