Optimum Moisture Content and Maximum Dry Density

Q. A cohesive soil yields a maximum dry density of 1.8 g/cc at an OMC of 16% during a Standard Proctor test. If the value of G is 2.65, the maximum dry density it can be further compacted to is ____ g/cc

1. 1.86

Q. Consider the following statements:
1. 'Relative compaction' is not the same as 'relative density'.
2. Vibrofloatation is not effective in the case of highly cohesive soils.
3. 'Zero air void line' and 100% saturation line are not identical.
Which of these statements is/are correct?

1. 1 and 2
2. 1 and 3
3. 2 and 3
4. 3 along

Q. A saturated undisturbed sample from a clay strata has moisture content of 22.22% and specific weight of 2.7. Assuming ${\gamma }_w=10kN/m^3$, the void ratio and the saturated unit weight of the clay, respectively are

1. $0.6and16.875kN/m^3$
2. $0.3and20.625kN/m^3$
3. $0.6and20.625kN/m^3$
4. $0.3and16.975kN/m^3$

Q. Soil is compacted at which one of the following when a higher compactive effort produces highest increase in dry density?

1. Optimum water content
2. Dry side of the optimum moisture content
3. Wet side of the optimum moisture content
4. Saturation moisture content

Q. In laboratory compaction tests, the optimum moisture content of soil decreases

1. with increase of compaction energy and with decrease of coarse grains in the soil
2. with decrease of compaction energy and with increase of coarse grains in the soil
3. with increase of both compaction energy and coarse grains in the soil
4. with decrease of both compaction energy and coarse grains in the soil.

Q. The zero-air voids curve is non-linear owing to

1. The standard proctor test data of dry density and corresponding water content plotting as a non-linear curve
2. The dry density at 100% saturation being a non-linear function of the void-ratio
3. The water content altering during compaction
4. The soil being compacted with an odd number of blows

Q. In a compaction test, G, w, S and e represent the specific gravity, water content, degree of saturation and void ratio of the soil sample, respectively. If ${\gamma }_w$ represents the unit weight of water and ${\gamma }_d$ represents the dry unit weight of the soil, the equation for zero air voids line is

1. ${\gamma }_d=\frac{G_{{\gamma }_w}}{1+Se}$
2. ${\gamma }_d=\frac{G_{{\gamma }_w}}{1+Gw}$
3. ${\gamma }_d=\frac{Gw}{1+{\gamma }_{w}S}$
4. ${\gamma }_d=\frac{Gw}{1+Se}$

Q. Following statement are made on compacted soil, where in DS stands for the soils compacted on dry side of optimum moisture content and WS stand for the soils compacted on wet side of optimum moisture content. identify incorrect statement:

1. Soil structure is flocculated on DS and dispersed on WS
2. Construction pore water pressure is low on DS and high on WS
3. On drying, shrinkage is high on DS and low on WS
4. On access to water, swelling is high on DS and less on WS

Q. A sample of sand has a volume of 1000 ml in its natural state. Its minimum volume when compacted is 750 ml. When gently poured into a measuring cylinder, its possible maximum volume is 1320 ml. What is the relative density?

1. 56
2. 52
3. 58
4. 60

Q. Consider the following statements:
1. Cohesionless soils experience relatively quicker compression under load.
2. Clays compacted dry-of-optimum compress more rapidly.
3. Clays compacted wet-of-optimum consolidate more under low stress range.
Which of these statements are correct?

1. 1, 2 and 3
2. 1 and 2 only
3. 1 and 3 only
4. 2 and 3 only

Q. Which one of the following state is the soil compacted. When a higher compactive effort produces highest increase in dry density?

1. Optimum water content
2. Dry side of the optimum moisture content
3. Wet side of the optimum moisture content
4. Saturation moisture content

Q. Which of the following statement is INCORRECT?

1. At low strain, strength of cohesive soils compacted dry of optimum is higher than those compacted wet of optimum.
2. A clayey soil sample compacted wet of optimum water content exerts greater swelling pressure.
3. Soil sample compacted dry of optimum shrinks appreciably less then that compacted wet of optimum
4. Dry density increases due to compaction.