B.TECH - Semester 5 geotechnical engineering Question Paper 2021 (mar)
Practice authentic previous year university questions for better exam preparation.
Sample Questions
- Derive from phase diagram expression for dry unit weight of soil in terms of specific gravity, void ratio and unit weight of water.
- Differentiate between welt graded, poorly graded and gap graded soils.
- Write down Terzhaghi's one dimensional consolidation equation. What are its assumptions.
- Define compression index. How it can be determined?
- Define sensitivity, thixotropy and critical void ratio ( $5 \times 4=20$ Marks) Answer any one full questions from each Module.
- (a) The percentage air voids of a natural sand deposit is 34 percent. For determining the relative density dried sand from the statum was first filled loosely in a $1000 \mathrm{~cm}^{3}$ mould and vibrated. The loose dry mass in the mould was 610 g ...
- (b) Tests on a remoulded clay sample indicated the following observations:
- (i) Natural water content $=45 \%$ (ii) Liquid limit 55\% (iii) Plastic limit = 28\% Calculate (1) Liquidity index (2) Plasticity index (3) Compression index
- (a) $1500 \mathrm{~m}^{3}$ of earth fill is to be constructed. How many cubic meters of soil are required to be excavated from borrow pit in which the void ratio is 0.90 , if the void ratio of earth fill is to be 0.70 .
- (b) Explain the plasticity chart as per IS classification system. Classify the soil having Liquid limit $=38 \%$ and Plastic limit $=28 \%$ as per IS classification system.
- (a) Explain (i) Effective stress principle (ii) Critical hydraulic gradient 10
- (b) Water table in a deposit of uniform sand is located at 2 m below the ground surface, Void ratio and specific gravity of soil particles are 0.85 and 2.7 respectively. Compute the total and effective stresses at a depth of I m and 8 m below the gro...
- (a) Explain how the average permeability of stratified deposits can be determined.
- (b) A laboratory compaction test on a soil having specific gravity 2.68 gave a maximum dry density of $18 \mathrm{kN} / \mathrm{m}^{3}$ at a water content of $17 \%$. Determine the porosity, degree of saturation, air content and percentage air voids ...
- (a) Explain square root of time fitting method for determination of coefficient of consolidation.
- (b) A layer of soft saturated clay 5 m thick lies under a newly constructed building. The effective stress due to overlying strata on the clay layer is 300 kPa and the new construction increases the overburden pressure by 120 kPa . If the compression...
- (a) Differentiate between normally consolidated and over consolidated states. 10
- (b) In the laboratory a 2 cm thick soil sample takes 25 minutes to reach $30 \%$ degree of consolidation. Find the time take for a 5 m thick layer in field to reach 40\% consolidation. Assume double drainage in both cases. Module - IV
- (a) Explain different types of slope failures.
- (b) Two identical specimens of dry sand are tested in the triaxial cell apparatus with confining pressure of $150 \mathrm{kN} / \mathrm{m}^{\prime}$ and $250 \mathrm{kN} / \mathrm{m}^{2}$ respectively. If the angle of internal fiction of sand is $30^...
- (a) Explain Swedish circle method for analysis of finite slopes.
- (b) A soil has an unconfined compressive strength of 120 kPa . In a triaxial test, a specimen of this soil failed at a deviator stress of 160 kPa when the cell pressure was 40 kPa . Determine the shear parameters of the soil. ( $\mathbf{4} \boldsymbo...