Proctor Tests

Q. A clayey soil has a maximum dry density of 16 kN/$m^3$ and optimum moisture content of 12%. A contractor during the construction of core of an earth dam obtained the dry density 15.2kN/$m^3$ and water content 11%. This construction is acceptable because

1. The density is less than the maximum dry density and water content is on dry side of optimum
2. The compaction density is very low and water content is less than 12%
3. The compaction is done on the dry side of the optimum
4. Both the dry density and water content of the compacted soil are within the desirable limits

Q. The field density and field moisture content of a soil can be determined by
1. Core cutter method
2. Sand replacement method
3. Proctor compaction test
4. Modified proctor compaction test

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

Q. Compaction of an embankment is carried out in 500mm thick layers. The rammer used for compaction has a foot area of 0.05$m^2$ and the energy imparted in every drop of rammer is 400 N-m. Assuming 50% more energy in each pass over the compacted area due to overlap, the number of passes required to develop compactive energy equivalent to Indian Standard light compaction for each layer would be

1. 10
2. 16
3. 20
4. 26

Q. In a standard proctor test, 1.8 kg of moist soil was filled the mould (volume = 944 cc) after compaction. A soil sample weighing 23 g was taken from the mould and ovendried for 24h at a temperature of ${110}^{\circ }C$. Weight of the dry sample was found to be 20 g. Specific gravity of soil solids is G = 2.7. The theoretical maximum value of the dry unit weight of the soil at that water content is equal to

1. 4.67 kN/$m^3$
2. 11.5 kN/$m^3$
3. 16.26 kN/$m^3$
4. 18.85 kN/$m^3$

Q. A cohesive soil yields a maximum dry density of $16kN/m^3$ during a standard Proctor Compaction test. If the specific gravity is 2.65, what would be its void ratio?

1. 0.552
2. 0.624
3. 0.712
4. 0.583

Q. OMC-SP and MDD-SP denote the optimum moisture content and maximum dry density obtained from standard Proctor Compaction test, respectively. OMC-MP and MDD-MP denote the optimum moisture content and maximum dry density obtained from the modified proctor Compaction test, respectively. Which one of the following is correct?

1. OMC-SP < OMC-MP and MDD-SP < MDD-MP
2. OMC-SP > OMC-MP and MDD-SP < MDD-MP
3. OMC-SP < OMC-MP and MDD-SP > MDD-MP
4. OMC-SP > OMC-MP and MDD-SP > MDD-MP

Q. For conducting a Standard Proctor Compaction Test, the weight of hammer (P in kg), the fall of hammer (Q in mm), the number of blows per layer (R) and the number of layers (S) required are respectively.

1. P Q R S
   5.89 550 50 3
2. P Q R S
   4.89 450 25 3
3. P Q R S
   3.60 310 35 4
4. P Q R S
   2.60 310 25 3

Q. As per the compaction specification, a highway fill of 1.5 km length has to be compacted to 90% of Indian standard light compaction test dry density. A borrow pit available near the project site has a dry density of 1.78 g/cc at 100% compaction and a void ratio of 0.63. The volume of borrow pit material required to construct a highway fill of height 5 m and top width of 10.5 with side slope of 1V:2H is (Assume G=2.7)

1. 153750 m${}^3$
2. 158937m${}^3$
3. 148731m${}^3$
4. 57486m${}^3$

Q. Consider the following:
1. Increase in shear strength and bearing capacity
2. Increase in slope stability
3. Decrease in settlement of soil
4. Decrease in permeability
Which of the above with respect to compaction of soil is/are correct?

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

Q. Two series of compacting tests were performed in the laboratory on an inorganic clayey soil employing two different levels of compaction energy per unit volume of soil. With regard to the above test, the following two statements are made.

(i) The optimum moisture content is expected to be more for the test with higher energy.

(ii) The maximum dry density is expected to be more for the test with higher energy.

The correct option evaluating the above statement is

1. Only I is True
2. Only II is True
3. Both I and II are True
4. Neither I nor II is True

Q. Directions: The following items consists of two statements; one labelled as ' Assertion (A)' and the other as 'Reason (R)'. You are to examine these two statements carefully and select the answers to these items using the codes given below:

Assertion (A): In a compaction test at ${\gamma }_{dmax}$ and OMC, the degree of saturation is never 100%.

Reason (R): It is not possible to expel all the air entrapped in soil by compaction.

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