The unified system of soil grouping

No 4 sieve= 50%

200 sieve= 200%= 72

GW= well graded fine to gravel

Question 2

High plasticity= LL 50

Low plasticity= LL 50

PI= LL- PL = 52-20 = 32. This soil is above A-line, this soil is inorganic of high plasticity.

Question 3

200*0.075mm= 58.6 = > 35%,

LL =2g, PL = 1g

Pl=ll-pl = 2g – 1g= 10

10 is less than 40 thus it belongs to A-4 group, soil B1 (5-6ft))

The limits fall below the A-line, this soil is classified as OH and MH. These are inorganic soil of medium plasticity.

Question 4

Part a)

US sieve no Mass of soil retained on each sieve C.M of each sieve Percent finer= m-cm/m * 100

4 0 0 100

10 18.5 18.5 95.61

20 53.2 71.7 82.93

40 90.5 162.2 61.44

60 81.8 244 42.07

100 92.2 336.2 20.18

200 58.5 394.7 6.29

pan 26.5 421.2 0

Total = 421.2

Part b)

From the graph above 0.23mm diameter is about 10% finer, 0.33mm is 30% and 0.48mm is 60% finer.

Part c)

Uniformity coefficient= Dm/Dn= 0.48/0.23 = 2.08

Part d)

Coefficient of gradation= D230/ D60 * D10 = 0.332 mm/0.48mm *0.23 mm= 0.99

Question 5

Li= 0.73, wn= 44.5%, PI= 24.7

LI= Wn–PL/PI = 0.73= 44.5-PL/24.7 =

Plastic limit= 26.47%

Question six

200 sieve= 60

Ll= 50

Pl=30

A fine grained soil contains 50% or more materials that are smaller than no.200 sieve size

Like 50% liquid limit

PI= 0.73(55-20) = 25.554

WP= cl- pl= 55-30= 25%

Question 7

Soil A

Sieve= 36min, 72

Liquid limit= 41 min, 52

PI= 11 min, 21

Group index= 72-35 (0.2 + 0.005(52-40)) + 0.01(72-15)(21-10)

= 15.89 = 16

Category = A- 7-5 (16)

Soil E

48-35(0.2 + 0.005(30-40)) + 0.01(48 -15)(11-10)

2.28

A-6(2)

Soil B

Sieve no. 200, 36 min = 58

Liquid limit, 40max. 38

PI, 11 min, 12

58-35(0.2 + 0.005(38-40)) + 0.01(58 -15)(12-10)

5.23

Category A-6(5)

Soil D

Sieve no 200, 36 min , 82

Liquid limit, 40 max, 32

PI, 11 min, 12

82-35(0.2 + 0.005(32 – 40) ) + 0.01(82 -15) (12-10)

8.86

Category A-6(9)

SOIL C

Sieve no 200, 36 min 64

Liquid limit, 41. 41

PI, 11, 12

64-35(0.2 +0.005(41-40)) + 0.01(64 – 15) (14 10)

7.905

Category, A-7-6(9)