1. A compacted sample of soil with a bulk unit weight of 19.62 KN/m3 has a water content of 15 per cent. What are its dry density, degree of saturation and air content? Assume G = 2.65
2. Explain with sketches the following structures i) Single grained ii) Honey combed iii) flocculent
3. A soil sample weighing 16 KN/m3 has water content of 32%. The Specific gravity of soil particle is 2.65. Determine I) Void ratio ii) Porosity iii) Degree of saturation.
4. Two clays A and B have the following properties:
Clay A Clay B
Liquid limit 44 per cent 55 per cent
Plastic limit 29 per cent 35 per cent
Natural water content 30 per cent 50 per cent
Which of the clays, A or B, would experience larger settlement under identical loads? Why?
5. Define effective size of particle in sieve analysis.
6. Define and explain the significance of uniformity coefficient and coefficient of curvature
7. With the help of particle size distribution curves Show the following types of soils: i) Well graded ii) Uniformly graded (iii) Gap Graded
8. Define Sieve Analysis and Sedimentation Analysis and what is the necessity of these two analyses?
9. What is a Zero Air Voids line? Draw a Compaction curve and show the Zero Air Voids line
10. What is the relationship between moist unit weight and dry unit weight? Write the relevant equation and describe the variables.
11. Derive the relation between void ratio and porosity
12. Why do we perform sedimentation analysis?
13. a) Define I) Bulk density ii) Relative density iii) dry density
14. What is the effect of compaction on engineering properties of soils?
15. Describe in detail how to distinguish between
i) GW or GP or GM or GC
ii) SW or SP or SM or SC
16. Distinguish between: i) Density index and liquidity index ii) Activity and sensitivity
c) Describe gendering method for the determination of water content of a soil sample in a laboratory.
2.a) Describe grain size distribution test procedure and the use of this result in classifying coarse grained soil.
b) Define Plasticity index and shrinkage limit. Explain their use in soil engineering practice.
2.a) Explain with the help of particle size distribution curves the following types of soils i) Well graded ii) Uniformly graded
b) Describe how Plastic limit of the soil is determined in the laboratory?
PART -B
1. A laboratory compaction test on soil having specific gravity equal to 2.67 gave a maximum dry unit weight of 17.8 KN/m3 and a water content of 15 per cent. Determine the degree of saturation, air content and percentage air voids at the maximum dry unit weight. What would be the theoretical maximum dry density corresponding to zero air voids at optimum water content?
2. An earthen embankment of 106 m3 volume is to be constructed with a soil having a void ratio of 0.80 after compaction. There are three borrow pits marked A, B and C having soils with void ratios of 0.90, 1.50 and 1.80, respectively. The cost of excavation and transporting the soil is Rs 0.25, Rs 0.23 and Rs 0.18 per m3, respectively. Calculate the volume of soil to be excavated from each pit. Which borrow pit is the most economical? (Take G = 2.65)
3. A 110 cm3 sample of wet soil has a mass of 212 g and a degree of saturation of 100%. When oven-dried, the mass is 162 g. Determine the dry unit weight (dry density in this case because of the units used), water content, void ratio, and specific gravity of the soil particles.
4. A. What are Atterberg limits for soil and why it is necessary?
B. You are given the following results from Atterberg Limits testing on a soil sample (PL = 23%, LL = 50%) collected from a boring on a local project site. What is the plasticity index for this soil? If the soil is fine grained and above A – Line in Plasticity Chart, what is the IS classification Symbol for this soil? If the natural moisture content is 56.3% prior to Atterberg limits testing. What does the natural moisture content result tell you about the soil in-situ (i.e. “in place”)?
5. Define Porosity and Void ratio
b) By three phase diagram show that the degree of saturation can be expressed in terms of mass unit weight g, water content w and specific gravity of soil grains G, and unit weight of water.
c) A soil sample weighing 16 KN/m3 has water content of 32%. The Specific gravity of soil particle is 2.65. Determine I) Void ratio ii) Porosity iii) Degree of saturation.
b) With usual notation show that g = ( G + S.e) gw / 1 + e
c) A saturated soil sample has a water content of 25% and unit weight of 2g/cc (20 KN/m3). Determine i) the specific gravity of the solid particles ii) Dry weight iii) Void ratio
Define Porosity and Void ratio
b) By three phase diagram show that the degree of saturation can be expressed interms of mass unit weight g, water content w and specifi gravity of soil grains G, and unit weight of water.
c) A soil sample weighing 16 KN/m3 has water content of 32%. The Specific gravity of soil particle is 2.65. Determine I) Void ratio ii) Porosity iii) Degree of saturation.
2.a) Define and explain the significance of uniformity coefficient and coefficient of curvature
b) Explain pycnometer method of finding the specific gravity of soil sample
6.a) What are the methods adopted for determining the density of soil in the field? Explain any one method and its limitations.
An earth embankment is to be compacted to a density of 19 kN/ m³ at a moisture Content of 14%. The in-situ bulk density and water content of the borrow pit are 18 kN/m³ and 8% respectively. How much excavation should be carried out from the borrow pit for each m³ of the embankment?
Describe the Proctor ‘Compaction Test’ and give its use for construction of embankments. Explain why soils are compacted in the field. How is the degree of compaction ensured in the field ?
A soil has been dumped loosely from a scraper. It has a unit weight of 16 kN/m³ , a water content of 10.5% and a specific gravity of solids of 2.68. Find the void ratio, porosity, and unit weight of soil in loose condition. For compaction an optimum water content of 15% is necessary. How much water should be added to in litres/m³ of soil to raise the water content to the optimum water content?
The maximum dry density and optimum moisture content of a soil from Standard Proctor’s test are 1.8g/cm³ and 16% respectively. Compute the degree of saturation of the sample, assuming the specific gravity of soil grains as 2.70.
b) A soil in the borrow pit is at a dry density of 1.7 Mg/ m³ with water content of 12%. If a soil mass of 2000 cubic metre volume is excavated from it and compacted in an embankment with a porosity of 0.32, calculate the volume of the embankment which can be constructed out of this material. Assume G= 2.70.