Consistency Limits

Q. Consistency Index of a clayey soil is [LL = Liquid Limit, PL = Plastic Limit, PI = Plasticity Index, w = Natural moisture content]

1. $\frac{LL-w}{PI}$
2. $\frac{w-LL}{PI}$
3. $LL-PL$
4. 0.5 w

Q. The liquid limit and plastic limit of clay soil are 45 % and 25% respectively. The soil consists of 30% of particles finer than the clay size. The classification of the clay based on activity is

1. Normal
2. Active
3. Inactive
4. Low active

Q. A soil has liquid limit = 35, plastic limit = 20, shrinkage limit = 10 and natural moisture content = 25%. What will be its liquidity Index, plasticity Index and shrinkage Index?

1. 0.67, 15 and 25
2. 0.33, 15 and 10
3. 0.67, 25 and 15
4. 0.33, 20 and 15

Q. While computing the values of limits of consistency indices, it is found that liquidity index, has a negative value.
Consider the following comments on this value:

1. Liquidity index cannot have a negative value and should be taken as zero.
2. Liquidity index can have a negative value.
3. The soil tested is in semisolid state and stiff
4. The soil tested is in medium soft state.

Which of these statement are correct?

1. 1 and 4
2. 1 and 3
3. 2 and 4
4. 2 and 3

Q. If an unconfined compressive strength of $4kg/c{m}^2$ in the natural state of clay reduces by four times in the remoulded state, then its sensitivity will be

1. 1
2. 2
3. 4
4. 8

Q. Given that Plasticity Index (PI) of local soil = 15 and PI of sand = zero, for a desired PI of 6, the percentage of sand in the mix should be

1. 70
2. 60
3. 40
4. 30

Q. The consistency of a saturated cohesive soil is a affected by

1. water content
2. particle size distribution
3. density index
4. coefficient of permeability

Q. Consistency as applied to cohesive soils is an indicator of its

1. density
2. moisture content
3. shear strength
4. porosity

Q. The liquid limit and plastic limit of sample are 65% and 29% respectively. The percentage of the soil fraction with grain size finer than 0.002 mm is 24. The activity ratio of the soil sample is

1. 0.50
2. 1.00
3. 1.50
4. 2.00

Q. A specimen of clayey silt contains 70% silt size particles. Its liquid limit = 40 and plastic limit = 20. In liquid limit test, at moisture content of 30% required number of blows was 50. Its plasticity index, activity and consistency index will respectively be

1. 20, , 0.67 and 0.5
2. 20, 1.5 and 2.0
3. 30, 1.5 and 0.72
4. 20, 0.286 and 0.38

Q. Consider the following statements:
1. Activity is a property typical of clay soils.
2.An activity value of 7 in a clay soil is indicative of the presence of montmorillonite mineral.
3. An activity value of 7 in a clay soil is indicative of the presence of illite mineral.

Which of these statement are correct?

1. 1, 2, and 3
2. 1 and 2 only
3. 1 and 3 only
4. 2 and 3 only

Q. Assertion (A): A soil is at its liquid limit if the consistency index of the soil is equal to zero.

Reason (R): The consistency index of a soil is defined as ratio of (liquid limit minus the natural water content) to (natural water content minus plastic limit).

1. both A and R are true and R is the correct explanation of A
2. both A and R are true but R is not a correct explanation of A
3. A is true but R is false
4. A is false but R is true

Q. The plasticity index and the percentage of grain size finer than 2 microns of a clay sample are 25 and 15, respectively. Its activity ratio is

1. 2.5
2. 1.67
3. 1.0
4. 0.6

Q. The laboratory tests on a sample yielded the following results:
Plasticity index : 32%
Liquidity index : 0.15
Activity number : 1.58
Which of the following inferences can be drawn?
1. The soil is very stiff.
2. The soil is medium soft.
3. The soil is highly plastic.
4. The soil is medium plastic.
5. The soil is active.
Select the correct answer using the codes given below:

1. 1, 3 and 5
2. 1, 3, and 4
3. 2, 3 and 5
4. 1, 2 and 4

Q. Assertion (A): If the water table is very near to the subgrade of the road, it will ultimately cause cracking of the road surface.

Reason (R): The consistency of the soil will change from plastic to liquid state leading to its volumetric decrease.

1. both A and R are true and R is the correct explanation of A
2. both A and R are true but R is not a correct explanation of A
3. A is true but R is false
4. A is false but R is true

Q. A Clayey soil has liquid = $W_L$; plastic limit = $W_P$ and natural moisture content = w. The consistency index of the soil is given by

1. $\frac{W_L-W}{W_L-W_P}$

2. $\frac{W_L-W_P}{W_L-W}$

3. $\frac{W_P-W}{W_L-W_P}$

4. $\frac{W_P-W}{W_L-W_P}$

Q. A fine grained soil has 60% (by weight) silt content. The soil behaves as semi-solid when water content is between 15% and 28%. The soil behaves fluid-like when the water content is more than 40% .The 'Activity' of the soil is

1. 3.33
2. 0.42
3. 0.30
4. 0.20

Q. Match List -I (Unit/Test) with List -II (Purpose) and select the correct answer using the codes given below the lists:

Lists -I
A. Casegrande's apparatus

B. Hydrometer

C. Plate load test

D. Oedometer

Lists -II

1. Determination of grain size distribution

2. Consolidation characteristics

3. Determination of consistency limits.

4. Determination of safe bearing capacity of soil

Codes:

1. A B C D
   1 3 2 4
2. A B C D
   1 3 4 2
3. A B C D
   3 1 2 4
4. A B C D
   3 1 4 2

Q. Consider the following statements:

1. Increase in volume of soil sample without external constraints on submergence in water is termed as free swell.
2. Clay soil rich in montmorillonite exhibits low activity.
3. Shear strength of all soils at liquid limit is zero.
4. Generally, the reduction in volume ceases with further loss of moisture at shrinkage limit.

Which of the above statements are correct?

1. 1 and 2
2. 2 and 3
3. 1 and 4
4. 3 and 4