Apr 6, 20202 min

Soil Mechanics (41-60)

Updated: Apr 9, 2020

41.If the material of the base of the Casagrande liquid limit device on which the cup containing soil paste drops is softer than the standard hard rubber, then

the liquid limit of soil always increases


42. According to IS classification, the range of silt size particles is 0.075 mm to 0.002 mm


43. Highway Research Board (HRB) classification of soils is based on both particle size composition and plasticity characteristics


44. Inorganic soils with low compressibility are represented by ML


45. Sand particles are made of rock minerals


46. The clay mineral with the largest swelling and shrinkage characteristics is

montmorillonite


47. Dispersed type of soil structure is an arrangement comprising particles having

face to face or parallel orientation


48. Effective stress is important because it is a function of engineering properties of soil


49. Rise of water table above the ground surface causes equal increase in pore water pressure and total stress


50. The total and effective stresses at a depth of 5 m below the top level of water in a swimming pool are respectively 0.5 kg/cm2 and zero


51. If the water table rises upto ground surface, then the effective stress is reduced due to increase in pore water pressure only but total stress does not change


52. The critical hydraulic gradient ic of a soil mass of specific gravity G and voids ratio e is given by


53. Quick sand is a flow condition occurring in cohesionless soils


54. The hydraulic head that would produce a quick condition in a sand stratum of

thickness 1.5 m, specific gravity 2.67 and voids ratio 0.67 is equal to 1.5 m


55. Physical properties of a permeant which influence permeability are

both viscosity and unit weight


56. The greater the unit weight, the greater is permeability


57. Effective stress on soil decreases both voids ratio and permeability


58. If the permeability of a soil is 0.8 mm/sec, the type of soil is sand


59. Which of the following methods is more suitable for the determination of permeability of clayey soil ? falling head method


60. Which of the following methods is best suited for determination of permeability of coarse-grained soils ? constant head method

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