Apr 7, 20202 min

Soil Mechanics (81-100)

Updated: Apr 10, 2020

81. Degree of consolidation is directly proportional to time and inversely proportional to square of drainage path


82. Time factor for a clay layer is directly proportional to permeability

of soil


83. If the time required for 50% consolidation of a remoulded sample of clay with single drainage is t, then the time required to consolidate the same sample of clay with same degree of consolidation but with double drainage is t/4


84. Clay layer A with single drainage and coefficient of consolidation Cv takes 6

months to achieve 50% consolidation. The time taken by clay layer B of the same

thickness with double drainage and coefficient of consolidation Cv/2 to achieve the same degree of consolidation is 3 months


85. Coefficient of consolidation for clays normally decreases with increase in liquid limit


86. Direct measurement of permeability of the specimen at any stage of loading can be made only in fixed ring type consolidometer


87. Compressibility of sandy soils is much less than that of clayey soils


88. coefficient of compressibility of an over-consolidated clay is less than

that of a normally consolidated clay


89. Coefficient of compressibility is different for different types of soils

and also different for a soil under different states of consolidation


90. The ultimate consolidation settlement of a structure resting on a soil

decreases with the increase in the initial voids ratio


91. The ultimate consolidation settlement of a soil is directly proportional to the

compression index


92. A normally consolidated clay settled 10 mm when effective stress was increased from 100 kN/m2 to 200 kN/ m2. If the effective stress is further increased from 200 kN/ m2 to 400 kN/ m2, then the settlement of the same clay is

10 mm


93. Coarse grained soils are best compacted by a vibratory roller


94. With the increase in the amount of compaction energy optimum water content decreases but maximum dry density increases


95. The maximum dry density upto which any soil can be compacted depends upon both moisture content and amount of compaction energy


96. Relationship between dry density γd, percentage air voids na, water content w

and specific gravity G of any soil is


97. For better strength and stability, the fine grained soils and coarse grained soils are compacted respectively as wet of OMC and dry of OMC


98. Select the incorrect statement Effective cohesion of a soil can never

have a negative value


99. For a loose sand sample and a dense sand sample consolidated to the same effective stress ultimate strength is same but peak strength of dense sand is greater than that of loose sand


100. The shear strength of a soil decreases with decrease in normal

stress

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