1.The slaking of the clay occurs when clayey soil is dried ________
a) below the shrinkage limit
b) above the shrinkage limit
c) below the plastic limit
d) above the plastic limit
Explanation: When the clayey soil is dried below its shrinkage limit, it will attain its minimum volume. When this is suddenly immersed in water it causes slaking.
2. Slaking is due to the ______ into the drying of the soil below the shrinkage limit.
a) entry of water
b) exit of water
c) entry of air
d) exit of air
Explanation: When the water enters the voids (containing air during drying process), due to immersion, menisci is formed, causing high pressures and subsequent explosion of the voids leading to the disintegration soil structure.
3. The bulking of sand is maximum when the water content is _________
a) 0
b) 5 to 6%
c) 15 to 17%
d) 20 to 21%
Explanation: The bulking of sand is maximum when the water content is 5 to 6%. Saturating the soil above 5 or 6% will result in destruction of the menisci and decrease in the volume.
4. Frost heave is defined as ___________
a) Rise of ground water surface
b) Freezing of water in soil
c) Increase in volume due to freezing
d) None of the mentioned
Explanation: Rise of ground water surface in a soil mass due to frost action is termed as frost heave.
5. If the void ratio is 40% in saturated soil, then the expansion of the soil will be __________
a) 5 %
b) 2.3 %
c) 3.6 %
d) 4 %
Explanation: There is an increase of about 9% in the volume, when water is converted in to ice. Therefore
Expansion of the soil = 0.009×40
=3.6 %.
6. What are the types of soils, that are prone to frost action?
a) Sand and Silt
b) Clay
c) None of the mentioned
d) All of the mentioned
Explanation: Only silts and fine sands are prone to frost action because these soils have large capillary rise due to relatively fine particles.
7. What is the maximum capillary tension for a tube of 0.05 mm diameter at 4°c?
a) 6.05 KN/m3
b) 0.617 KN/m3
c) 5.45 KN/m3
d) 3.00 KN/m3
Explanation: Maximum capillary height at 4°c is
(hC) max = 0.3084/d =0.617 m
Capillary tension = (hc) max × γmax
=6.05 KN/m3.
8. A well graded soil is said to be frost susceptible if more than _________
a) 10 % particle are smaller than 0.002 mm
b) 3 % particle are smaller than 0.002 mm
c) 3 % particle are smaller than 0.005 mm
d) 10 % particle are smaller than 0.005 mm
Explanation: A well graded soil is reckoned to be frost susceptible if 3 % particle are smaller than 0.002 mm and for poor graded soil 10 % particle are smaller than 0.002 mm.
9. The ground surface up to which water freeze is called ___________
a) Frost heave
b) Frost boil
c) Frost line
d) Ice lenses
Explanation: Frost line is the depth or boundary below the ground surface up to which water may freeze.
10. Silt soils are more susceptible to frost action than __________
a) Sand soil and Clayey soil
b) Gravel soil
c) None of the mentioned
d) All of the mentioned
Explanation: Silt soils have more plasticity index than sand and clays and hence the softening effect due to excess water will be more severe in silts.