SOIL MECHANICS AND

FOUNDATION INFORMATION

Consistency

FIELD IDETIFICATIONS

UNCONFIEND COMPRESSIUE ST. MG/CM2

Very soft

Easily penetrated several inches by fist

0.27

Soft

Easily penetrated several inches by thumb

0.27-0.54

Medium

Can be penetrated several inches by thumb with moderate effort.

0.54-1.08

Stiff

Readily indented by thumb but penetrated only with great effort

1.08-2.16

Very stiff

Readily indented by thumb nail

2.16-4.32

Hard

Indented with difficulty by thumb nail

>4.32

Penetration resistance & soil properties on basis of the standard penetration test.

No of blows per 30 CM(N)

Relative density DR

0-4

4-10

10-30

30-50

over 50

Very loose

Loose

Medium

Dense

Very dense

PROPERTIES OF Cohesionless soils

Type of soil

Angle of Internal friction

Unit WT&

Dry

Moist

Gravel common

35-45

1.75-2.20

-

Shingle loose

40

1.80

-

Sandy compact

40-45

2.05

-

Loose

35-40

1.90

-

Sand : fine Dry

30-35

1.60

-

Wet

00-30

1.85-1.95

-

Well graded compact

40-45

1.75-1.95

1.95-2.2

Loose

35-40

1.60-1.75

1.75-1.90

Sand : uniform

Fine or silty compact

Loose

35-40

30-35

1.60-1.75

1.50-1.60

1.7

1.6

Coarse or Medium compact

35-40

1.60-1.75

1.9

Loose

30-35

1.5-1.60

1.7

Crushed rock

Granite

Basalt

Sandstone

Broken chalk

35-40

35-40

35-40

35-40

1.60-2.10

1.75-2.25

1.30-1.90

0.95-1.30

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