Foundation Engineering

Foundation Engineering

Practical Portion

Experiment No. 1

Classification of Soil according

to USC and AASHTO

Classification System.

2Foundation Engineering ENGR. FAIZAN TAHIR

Designation

AASHTO M 145-91(2000)

ASTM D 2487-00


Scope

Tests Required for the Classification Sieve Analysis Atterberg Limit test

1. Liquid Limit Test2. Plastic Limit Test


Sieve Analysis

Column -1 Column -2

Standard Designation(mm)

Alternate Designation(in)

(75) 3 in.

(37.5) 1 ½ in.

(19) ¾ in.

(9.5) 3/8 in.

(4.75) No. 4

(2.00) No. 10

(0.840) No. 20

(0.420) No. 40

(0.250) No. 60

(0.15) No. 100

(0.075) No. 200

The sieves normally required are as follows


Procedure Take a sample about 500-g. of soil, when soil contain larger particles

(gravels), bigger soil sample will be required. Carefully check all the sieves and remove any particles sticking to the sieve

mesh. Sieves are arranged in the descending order of their sizes with a pan at

bottom. The sieving operation shall be conducted by lateral and vertical motion of the

sieves so as to keep the sample moving continuously over the sieve surface. The soil particles shall not be turned or manipulated through the sieves by

hand. Sieving shall be continued until not more than 1-percent by mass of the

residue passes any sieve during 60-seconds. Remove the sieves from the sieve shaker and carefully weigh the soil retained

on each sieve. Remove the particles sticking to the sieve mesh and should be included to the

weight retained. Tabulate the data and calculate the percentage passing as shown in the

following table.


Sieve Size (mm) Weight retained (gm)

Weight passed(gm)

(75)

(37.5)

(19)

(9.5)

(4.75)

(2.00)

(0.840)

(0.420)

(0.250)

(0.15)

(0.075)

pan

Percentage passing

)100

( weightTotalpassedWeight

Foundation Engineering 7ENGR. FAIZAN TAHIR

Liquid Limit Test

APPARATUS:1. Knife, 2. Grooving tool, 3. Balance, 4. Liquid limit apparatus, 5. Drying oven, 6. Containers for moisture content determination

Cassagrande Apparatus Grooving tools


Steps:

1. Sample as taken from the field 2. Sample after passing sieve No. 40 (About 100-g sample passing #40 Sieve)


12.7mm

3.. Making the paste 4. Paste in the Cassagrande cup

5. Groove in the paste 6. Groove closed for a length of 12.7-mm.Foundation Engineering 10ENGR. FAIZAN TAHIR

Test dataTest repetitions

1 2 3 4 5

Row -1Weight of can

(gm)

Row -2Weight of wetsoil + can (gm)

Row -3Weight of drysoil + can (gm)

Row -4Weight of dry

soil (gm)(Row.3 – Row.1)

Row -5Weight of

moisture (gm)(Row.2 – Row.3)

Row -6Moisture

content, m%(Row.5 / Row.4 x 100)

Row -7No. of blows N

Calculations:


Graph:

Liquid Limit

35

37

39

41

43

45

47

49

51

53

1 10 100

No. of Blows

Moi

stur

e C

onte

nt %


Plastic Limit TestSteps:1. Take abut 20-g of sample passing # 40 sieve, make a paste

2. Take 8-g of sample and deform it into ellipsoidal shaped mass.

3. Now roll the mass into a thread of uniform diameter throughout its length

Ellipsoidal shape sample Thread rolling


4. When the diameter of the thread becomes less than 3-mm. break the thread, and repeat last step again.

5. Continue performing step-3 until thread crumbles without reaching the Diameter of 3-mm.

6. Plasticity Index = Liquid Limit – Plastic Limit


Calculations:

Column-1 Column-2 Column-3 Column-4 Column-5 Column-6

Weight of can (gm)

Weight of wet soil thread + can (gm)

Weight of dry soil thread + can (gm)

Weight of dry soil (col.3 – col.1)

(gm)

Weight of moisture (col.2 –

col.3) (gm)

Moisture content, m% (col.5/col.4)


AASHTO SOIL CLASSIFICATION TABLETable


UNIFIED SOIL CLASSIFICATION TABLETable


Foundation Engineering

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