Soil Mechanics Questions PDF

## Soil Mechanics Question ### 1. Residual Soils - **What are they formed by?** - glaciers - wind - water - none of the above ### 2. Water Content of Soil - **Can it be greater than 100%?** - never be greater than 100% - take values only from 0% to 100% - be less t...

## Soil Mechanics Question ### 1. Residual Soils - **What are they formed by?** - glaciers - wind - water - none of the above ### 2. Water Content of Soil - **Can it be greater than 100%?** - never be greater than 100% - take values only from 0% to 100% - be less than 0% - be greater than 100% ### 3. Types of Soil - Which of the following types of soil is transported by gravitational forces? - loess - talus - drift - dune sand ### 4. Saturated Soil - A fully saturated soil is said to be - one phase system - two phase system with soil and air - two phase system with soil and water - three phase system ### 5. Degree of Saturation of Soil (S) - What is the valid range of S in percentage? - S > 0 - 0 < S < 100 - 0 ≤ S ≤ 100 - S ≤ 0 ### 6. Submerged Density of Soil - What is the expression for the submerged density of soil in terms of unit weight of water *yw*, specific gravity G and voids ratio e? - *yw(G+1) / (1+e)* - *yw(G-1) / (1-e)* - *yw(G+1) / (1-e)* - *yw(G-1) / (1+e)* ### 7. Dry Density of Soil - A soil has a bulk density of 22 kN/m³ and a water content of 10%. What is the dry density of the soil? ### 8. Soil Sieve Analysis - **Problem:** - A soil sample is subjected to a laboratory sieve analysis using a complete set of standard IS sieves. - Out of 3 kg of soil used in the test: - 1200 gm was retained on IS 600 micron sieve - 1500 gm was retained on IS 500 micron sieve - the remaining 300 gm was retained on IS 425 micron sieve - What is the uniformity coefficient for the soil? ### 9. Unit Weight of Soil - Select the correct statement. - unit weight of dry soil is greater than the unit weight of wet soil. - for dry soils, dry unit weight is greater than total unit weight. - unit weight of soil increases with submergence in water. - unit weight of soil decreases with submergence in water. ### 10. Voids Ratio - **What are possible values for the voids ratio of a soil mass?** - never be greater than unity - be zero - take any value greater than zero - take values between 0 and 1 - be equal to 1 ### 11. Porosity and Voids Ratio - If volume of voids is equal to the volume of solids in a soil mass, then what is the porosity and voids ratio (respectively)? - 1.0 and 0.0 - 0.0 and 1.0 - 0.5 and 1.0 - 1.0 and 0.5 ### 12. Soil Mass under Consideration - When the degree of saturation is zero, the soil mass under consideration represents which of the following? - one phase system - two phase system with soil and air - two phase system with soil and water - three phase system ### 13. Density Index (Ip) - Select the correct range based on the density index, Ip. - *Ip>0* - *Ip ≥ 0* - *0 < Ip < 1* - *0 ≤ Ip ≤ 1* ### 14. Air Content - If the degree of saturation of a partially saturated soil is 60%, then what is the air content of the soil: - 40% - 60% - 80% - 100% ### 15. Voids Ratio of Saturated Soil - If the water content of a fully saturated soil mass is 100%, what is the voids ratio of the sample? - less than specific gravity of soil - equal to specific gravity of soil - greater than specific gravity of soil - independent of specific gravity of soil ### 16. Ratio of Volume of Voids to Total Volume - What is the ratio of volume of voids to the total volume of the mass called? - air content - porosity - percentage air voids - voids ratio ### 17. Relative Density of Compacted Dense Sand - What is the approximate relative density of a compacted dense sand? - 0.4 - 0.6 - 0.95 - 1.20 ### 18. Relative Density of Sand - If the sand, in situ, is in its densest state, what is the relative density of the sand? - zero - 1 - between 0 and 1 - greater than 1 ### 19. Determining Water Content - Which of the following methods is most accurate for determining the water content of soil? - oven drying method - sand bath method - calcium carbide method - pycnometer method ### 20. Determining Water Content in the Field - For proper field control, what is the best suited method for quickly determining the water content of a soil mass? - oven drying method - sand bath method - alcohol method - calcium carbide method ### 21. Pycnometer - What is the use of a pycnometer? - water content and voids ratio - specific gravity and dry density - water content and specific gravity - voids ratio and dry density ### 22. Stoke's Law - When is Stoke's Law valid? - less than 0.0002 mm - greater than 0.2 mm - between 0.2 mm and 0.0002 mm - all of the above ### 23. Hydrometer Analysis - Which of these are true for hydrometer analysis in soil? - Both meniscus correction and dispersing agent correction are additive - Both meniscus correction and dispersing agent correction are subtractive - Meniscus correction is additive and dispersing agent correction is subtractive. - Meniscus correction is subtractive and dispersing agent correction is additive. ### 24. Hydrometer Method - What is the main difference between the hydrometer method and the pipette analysis? - the principle of the test - the method of taking observations - the method of soil preparation - all of the above ### 25. Measures of Particle Size Range - Which of the following is a measure of particle size range? - Effective Size - Uniformity coefficient - Coefficient of curvature - None of the above ### 26. Uniformity Coefficient - Which of the following statements is correct about the Uniformity Coefficient? - The uniformity coefficient represents the shape of the particle size distribution curve. - For a well graded soil, both uniformity coefficient and coefficient of curvature are nearly unity. - A soil is said to be well graded if it has most of the particles of about the same size. - None of the above ### 27. Uniformity Coefficient of Soil - What is the valid range for the uniformity coefficient of a soil? - Always less than 1 - Always equal to 1 - Equal to or less than 1 - Equal to or greater than 1 ### 28. Plasticity Index - What is the range of plasticity index (PI) for a soil classified as medium plasticity? - 0 < PI < 7 - 7 ≤ PI ≤ 17 - 17 < PI < 27 - PI ≥ 27 ### 29. Natural Water Content - If the natural water content of a soil mass lies between its liquid limit and plastic limit, then what is the state of the soil mass? - Liquid state - Plastic state - Semi-Solid state - Solid state ### 30. Liquidity Index - What is the formula for the liquidity index of a soil mass? - (Liquid Limit - Water Content) / Plasticity Index ### 31. Consistency Index - When is the plasticity index of a soil reported as negative? - When the plastic limit of a soil is greater than the liquid limit, the plasticity index is reported as - negative - zero - non-plastic (NP) - 1 ### 32. Toughness Index - How is the toughness index defined? - Plasticity Index / Consistency Index - Plasticity Index / Flow Index - Liquidity Index / Flow Index - Consistency Index / Liquidity Index ### 33. Admixture of Coarser Particles - What happens when you add coarser particles (like sand or silt) to clay? - Decrease in liquid limit and increase in plasticity index - Decrease in liquid limit and no change in plasticity index - Decrease in both liquid limit and plasticity index - Increase in both liquid limit and plasticity index ### 34. Uniform Soils - Select the correct statement about uniform soils. - A uniform soil has more strength and stability than a non-uniform soil - A uniform soil has less strength and stability than a non-uniform soil - Uniformity coefficient does not affect strength and stability. - Uniformity coefficient of a poorly graded soil is more than that of a well graded soil. ### 35. Soil Properties - Four soils (A, B, C, D) have been tested for Liquid Limit and Plastic Limit. - A: Liquid limit=0.50, Plastic limit=0.23 - B: Liquid limit=0.49, Plastic limit = 0.17 - C: Liquid limit = 0.43, Plastic limit = 0.21 - D: Liquid limit = 0.47, Plastic limit = 0.26 - Which soil contains the highest amount of clay particles? - Soil A - Soil B - Soil C - Soil D ### 36. Water Content at Liquid Limit - What is the water content of soil called at the boundary between plastic state and liquid state? - Liquid limit - Plastic limit - Shrinkage limit - Plasticity index ### 37. Plasticity Index - Which of the following soils has the highest plasticity index? - Sand - Clay - Silt - Gravel ### 38. Shear Strength of Soil at Liquid Limit - At its liquid limit, what can be said about the shear strength of the soil? - Same shear strength of small magnitude - Same shear strength of large magnitude - Different shear strengths of small magnitude - Different shear strengths of large magnitude ### 39. Lowering of Ground Water Table - What does Permanent lowering of the Ground Water Table (GWT) result in? - Settlements ### 40. Reasons for Settlements - What is the reason for settlements due to the lowering of GWT? - Increase in effective stress results in settlement of the soil. ### 41. Permeability Test - During a permeability test (falling head permeameter) on a soil sample, time intervals are noted for the drop of head from h₁ to h₂ and again from h₂ to h₃. Which of the following equations hold good? - h₃² = h₁h₂ - h₁² = h₂h₃ - h₂² = h₁h₃ - (h₁ - h₂) = (h₂ - h₃) ### 42. Total Stress and Effective Stress - If the saturated density of a soil is 2.1 t/m³, what is the total stress (t/m²) at a depth of 4 m in a saturated soil stratum? - 2.4 - 3.4 - 7.4 - 8.4 ### 43. Well-Graded Sand - Consider the following three statements about a well-graded sand: - Uniformity coefficient greater than 6 - Coefficient of curvature between 1 and 3 - Effective size greater than 1 mm - Which of those statements are correct? ### 44. Highway Research Board - What is NOT relevant regarding the Highway Research Board Classification system, for the dependency of group index of a soil? - The amount of material passing the 75-micron IS sieve - The liquid limit - The plastic limit - The shrinkage limit ### 45. Coefficient of Permeability - What is the coefficient of permeability of a file sand with an effective diameter of 0.2 mm using Hazen's formula? - 0.3 - 0.04 - 0.004 - 0.0004 ### 46. Modified Compaction Test - What are the standard weights and drop of hammer used during the Modified Compaction Test? - 2.50 kg and 300 mm - 4.89 kg and 450 mm - 2.50 kg and 450 mm - 4.89 kg and 300 mm ### 47. Efficiency of Sheepsfoot Rollers - On which factor does the efficiency of sheeps foot rollers depend? - The weight of the roller and the number of feet contact with the ground at a time. ### 48. Sheepsfoot Rollers - What type of soil are sheepsfoot rollers considered to be most suitable for compacting? - Clayey soils ### 49. Adding Lime to Clay Soil - Consider the following statements about the effects of adding lime to a clay soil. - **Statement 1:** MDD (Maximum Dry Density) and strength both increase. - **Statement 2:** MDD decreases but strength increases. - **Statement 3:** MDD and OMC (Optimum Moisture Content) both increase. - Which statement is correct? - Statement 1 only - Statement 2 only - Statement 3 only - None of these ### 50. Capillary Pressure - What is the statement about pore water pressure in capillary zones? - **Statement 1:** Pore water pressure is negative in the capillary zone. - **Statement 2:** Water is in tension in the capillary zone. - **Statement 3:** Capillary pressure is more in coarse grained soils. - Which of these statements are correct? - Statements 1 and 2 only - Statement 1 only - Statements 2 and 3 only - Statements 1, 2 and 3 ### 51. Fine Grained Soils - Are fine-grained soils difficult to drain? - Yes ### 52. Capillary Action in Soil Drainage - Capillary forces affect the drainage of fine-grained soils by acting on pore water. - **Statement 1:** Capillary forces act on pore water. - **Statement 2:** This is the correct explanation of why fine-grained soils are difficult to drain. - Which of these are correct? - Both statements are individually true and Statement 2 is the correct explanation of Statement 1. - Both statements are individually true, but Statement 2 is not the correct explanation of Statement 1. - Statement 1 is true but Statement 2 is false. - Statement 1 is false and Statement 2 is true. ### 53. Moisture Content and Density - When soil is at its *optimum moisture content*, what can be said about the density? - Density is known - It is the *specific moisture content* - It is the *retained moisture content* - It is the *absolute moisture content* ### 54. Soil Sample Weight - What is the formula for calculating the Moisture Content (MC) of a soil sample given the following weights: - An empty container weighs *W₁* - Container with soil sample *W₂* - Container and over-dried sand weighs *W₃* - (W₂-W₃)*100 / (W₁-W₂) - (W₂-W₃)*100 / (W₁-W₂) - (W₁-W₂)*100 / (W₂-W₃) -(W₁-W₂)*100 / (W₂-W₃) ### 55. Moisture Content and Dry Density - If the moisture content of a sample of soil is *w*, and the volume of Proctor's molded soil is *V*, what is the formula for calculating the dry density? - *w(1+w)/V* - *W/V(1+w)* - *W/V(1+w)* - *V(1+w)/W*