SSC JE Exam - shear strength direct shear vane triaxial tests compaction maximum dry density optimum moisture content Online Test (MCQ Quiz)

1. Which of the following tests is primarily used to determine the shear strength parameters (cohesion and angle of internal friction) of a soil sample in a relatively undisturbed or remolded state?

A) Compaction Test B) Direct Shear Test C) Vane Shear Test D) Triaxial Compression Test

2. The direct shear test is most suitable for determining the shear strength of which type of soil?

A) Highly cohesive clays B) Highly granular soils (sands and gravels) C) Soft silts D) Peat soils

3. In a direct shear test, the shear stress at failure is calculated as:

A) Applied axial load divided by the total area of the specimen B) Applied shear force divided by the area of the shear plane C) Applied shear force divided by the total area of the specimen D) Applied axial load divided by the area of the shear plane

4. The vane shear test is particularly useful for determining the undrained shear strength of:

A) Dry sand B) Saturated soft clays C) Gravelly soil D) Silty sand

5. What is the primary advantage of the vane shear test for soft clays?

A) It allows for precise measurement of pore water pressure. B) It minimizes disturbance to the soil structure. C) It can be performed under drained conditions. D) It provides accurate results for highly permeable soils.

6. In a triaxial compression test, the confining pressure is applied by:

A) A direct axial load B) Pore water pressure within the specimen C) Hydrostatic pressure from a surrounding fluid (usually water or air) D) The weight of the soil sample itself

7. Which type of triaxial test is performed at a slow strain rate to allow for pore water pressure dissipation and drainage?

A) Unconsolidated-Undrained (UU) test B) Consolidated-Undrained (CU) test C) Consolidated-Drained (CD) test D) Quick Test

8. The Unconsolidated-Undrained (UU) triaxial test is used to determine the shear strength of a soil under:

A) Drained conditions B) Long-term loading C) Short-term loading, undrained conditions D) Consolidated conditions

9. The Consolidated-Undrained (CU) triaxial test allows for the determination of shear strength parameters based on:

A) Total stress parameters only B) Effective stress parameters only C) Both total and effective stress parameters D) Undrained shear strength only

10. Compaction of soil is a process of:

A) Increasing the void ratio by adding water B) Decreasing the void ratio by expelling air C) Increasing the void ratio by applying shear stress D) Decreasing the void ratio by adding cement

11. The primary purpose of soil compaction is to:

A) Increase permeability and reduce strength B) Reduce permeability and increase strength C) Increase compressibility and reduce settlement D) Decrease compressibility and increase settlement

12. Which compaction test is commonly used in laboratories to determine the relationship between moisture content and dry density for a soil?

A) Direct Shear Test B) Vane Shear Test C) Proctor Compaction Test D) Consolidation Test

13. The Standard Proctor Compaction test uses a specific amount of energy applied by dropping a rammer from a specific height a specific number of times. What is the drop height of the rammer?

A) 305 mm B) 450 mm C) 600 mm D) 900 mm

14. In the Standard Proctor Compaction test, the rammer weighs approximately:

A) 1.5 kg B) 2.5 kg C) 4.9 kg D) 10 kg

15. The Modified Proctor Compaction test uses a higher compaction energy than the Standard Proctor test. This is achieved by:

A) Using a heavier rammer and a greater number of blows per layer B) Using a lighter rammer and a greater number of blows per layer C) Using a heavier rammer and a smaller number of blows per layer D) Using a lighter rammer and a smaller number of blows per layer

16. Maximum dry density (MDD) is the highest dry unit weight achievable for a soil at:

A) Any moisture content B) A specific moisture content C) The optimum moisture content D) Saturation moisture content

17. Optimum moisture content (OMC) is the moisture content at which a soil achieves its:

A) Minimum dry density B) Maximum dry density C) Maximum void ratio D) Minimum shear strength

18. For a given soil, as the compaction effort increases (e.g., from Standard to Modified Proctor), the OMC generally:

A) Increases B) Decreases C) Remains the same D) Becomes erratic

19. For a given soil, as the compaction effort increases (e.g., from Standard to Modified Proctor), the MDD generally:

A) Increases B) Decreases C) Remains the same D) Becomes erratic

20. Which of the following statements is true regarding the relationship between compaction energy and OMC/MDD?

A) Higher energy leads to higher OMC and lower MDD. B) Higher energy leads to lower OMC and higher MDD. C) Higher energy leads to higher OMC and higher MDD. D) Higher energy leads to lower OMC and lower MDD.

21. The shear strength of a compacted soil is generally:

A) Higher at OMC and lower at MDD B) Lower at OMC and higher at MDD C) Independent of OMC and MDD D) Highest when compacted significantly wet of OMC

22. In a direct shear test, if the normal stress is increased, the shear strength of the soil:

A) Decreases B) Increases C) Remains constant D) Becomes zero

23. The Mohr-Coulomb failure criterion is often used to represent the shear strength of soils. It is expressed as:

A) τ = c + σ tan φ B) τ = c - σ tan φ C) τ = σ + c tan φ D) τ = σ - c tan φ

24. In the Mohr-Coulomb equation (τ = c + σ tan φ), 'c' represents:

A) Normal stress B) Shear stress C) Cohesion D) Angle of internal friction

25. In the Mohr-Coulomb equation (τ = c + σ tan φ), 'φ' represents:

A) Cohesion B) Shear stress C) Normal stress D) Angle of internal friction

26. Which test is most appropriate for determining the undrained shear strength of a saturated clay in a laboratory, especially when dealing with sensitive clays?

A) Standard Proctor Test B) Direct Shear Test C) Vane Shear Test D) Triaxial Compression Test (UU)

27. The shear strength of a saturated clay under undrained conditions is often represented by:

A) c' and φ' (effective stress parameters) B) c_u and φ_u (total stress parameters) C) c_u and φ' (mixed parameters) D) c' and φ_u (mixed parameters)

28. The shear strength of a saturated clay under drained conditions is represented by:

A) c' and φ' (effective stress parameters) B) c_u and φ_u (total stress parameters) C) c_u and φ' (mixed parameters) D) c' and φ_u (mixed parameters)

29. A compaction curve plots dry density against moisture content. The peak of this curve represents:

A) The optimum moisture content and minimum dry density B) The optimum moisture content and maximum dry density C) The minimum moisture content and maximum dry density D) The maximum moisture content and minimum dry density

30. If a soil is compacted dry of optimum, its:

A) Shear strength is generally higher B) Compressibility is generally higher C) Permeability is generally higher D) All of the above

31. If a soil is compacted wet of optimum, its:

A) Shear strength is generally lower B) Compressibility is generally lower C) Permeability is generally lower D) All of the above

32. The 'zero air voids' curve on a compaction plot represents the theoretical maximum dry density achievable at different moisture contents if:

A) There is no water in the soil B) All air is expelled from the voids C) The soil is fully saturated D) The soil is completely dry

33. Which of the following factors affects the shear strength of a soil?

A) Type of soil B) Moisture content C) Compaction effort D) All of the above

34. In a direct shear test, the shear force at failure is applied:

A) Vertically B) Horizontally C) At an angle D) Axially

35. The 'quick' test in triaxial compression refers to:

A) A test performed very rapidly without drainage B) A test performed very slowly with drainage C) A test performed with a rapid application of load but allowing drainage D) A test performed to quickly determine OMC

36. The shear strength of a granular soil (like sand) under drained conditions is primarily dependent on:

A) Cohesion B) Angle of internal friction C) Water content D) Pore water pressure

37. The shear strength of a saturated clay under undrained conditions is primarily dependent on:

A) Angle of internal friction B) Cohesion C) Effective stress D) Permeability

38. The compaction test is important for construction because it helps ensure:

A) Maximum settlement of the fill material B) Minimum strength and stability of the fill material C) Sufficient strength and stability of the fill material D) High permeability of the fill material

39. In a triaxial test, the major principal stress is denoted by:

A) σ1 B) σ2 C) σ3 D) σd

40. In a triaxial test, the minor principal stress is denoted by:

A) σ1 B) σ2 C) σ3 D) σd

41. The deviator stress in a triaxial test is defined as:

A) σ1 - σ2 B) σ2 - σ3 C) σ1 - σ3 D) σ1 + σ3

42. The vane shear test is most suitable for:

A) Quick determination of shear strength of sand B) Field determination of undrained shear strength of soft clays C) Laboratory determination of drained shear strength of gravel D) Determination of compaction characteristics

43. Which parameter is NOT directly measured during a standard compaction test?

A) Moisture content B) Dry density C) Wet density D) Number of blows

44. The relationship between shear strength (τ), normal stress (σ), cohesion (c), and angle of internal friction (φ) is described by the:

A) Terzaghi's bearing capacity equation B) Mohr-Coulomb failure criterion C) Rankine's earth pressure theory D) Darcy's law

45. For a cohesionless soil (c=0), the shear strength is solely dependent on:

A) Cohesion B) Normal stress and angle of internal friction C) Water content D) Void ratio

46. If the OMC of a soil is 15% and its MDD is 1800 kg/m³, what is the dry density of the soil at a moisture content of 12% if it is compacted with the same energy?

A) Less than 1800 kg/m³ B) Exactly 1800 kg/m³ C) More than 1800 kg/m³ D) Cannot be determined without more information

47. Which type of triaxial test provides parameters for both total stress and effective stress analysis?

A) Unconsolidated-Undrained (UU) B) Consolidated-Undrained (CU) C) Consolidated-Drained (CD) D) All of the above

48. In the context of compaction, 'saturation line' or 'zero air voids' line represents the condition where:

A) The soil is completely dry B) All voids are filled with air C) All voids are filled with water D) The soil is partially saturated

49. The primary goal of performing a direct shear test at different normal loads is to:

A) Determine the optimum moisture content B) Obtain the compaction curve C) Establish the relationship between shear stress and normal stress to find c and φ D) Measure the rate of consolidation

shear strength direct shear vane triaxial tests compaction maximum dry density optimum moisture content - Online Test

Test Results