 MORE IN Geotechnical Engineering 2
VTU Civil Engineering (Semester 6)
Geotechnical Engineering 2
June 2014
Total marks: --
Total time: --
INSTRUCTIONS
(1) Assume appropriate data and state your reasons
(2) Marks are given to the right of every question
(3) Draw neat diagrams wherever necessary

1 (a) With a neat sketch of a sample, define
i) Area ratio
ii) Inside clearance
iii) Outside clearance
Also indicate recommended values.
6 M
1 (b) List and explain different types of samplers used in soil sampling.
8 M
1 (c) List the methods used for controlling ground water during excavation. Explain any one of these dewatering methods.
6 M

2 (a) List the assumptions made in Boussineq's and westergaards theories.
6 M
2 (b) Explain the: i) Pressure bulb;
ii) Pressure distribution on horizontal plane: iii) Pressure distribution on vertical plane.
8 M
2 (c) A point load of 1000kN acts at the ground surface. Compute the vertical stresses at 8m depth.
i) On the axis of the load;
ii) 2m away from the axis.
Use Boussineq's equations.
6 M

3 (a) What is flow net? What are its characteristics and uses?
8 M
3 (b) Explain with a neat sketch the method of locating phreatic line for a homogeneous earth dam without filter.
8 M
3 (c) Explain the terms:
ii) Piping failure
4 M

4 (a) List the assumptions and limitations of Rankine's Earth Pressure Theory.
4 M
4 (b) Explain the Culman's graphical construction for determination of active earth thrust.
8 M
4 (c) A retaining wall, 7.5m high retains cohesionless, horizontal back fill. The top 3m of fill has a unit weight of 18 kN/m3 and ϕ30° and the rest has a unit weight of 24kN/m2 and ϕ=20°. Determine using Rankine's theory, the distribution of active earth pressure and total active earth thrust.
8 M

5 (a) What are different types of slopes? Explain types of slope failures. What are the causes of slope failure?
6 M
5 (b) Explain the methods of slices for stability analysis of sloper.
8 M
5 (c) An embankment is to be constructed with C=30 kN/m2, ϕ=207deg;, r=18kN/m3, FS=2 and height 10m. Estimate the required side slope using Taylor's stability number.
6 M

6 (a) Explain the different modes of shear failure with the help of neat sketch.
6 M
6 (b) What are the assumptions made in Terzaghi's theory? Write the expressions for ultimate bearings capacity of strip footing, square and circular footing.
6 M
6 (c) A strip footing 1.2m wide is supported on a soil with its base at a depth of 1m below ground surface. The soil properties are C=15 kN/m2; ϕ=28°, γ'=10 kN/m3. Determine the ultimate bearing capacity if water table is:
i) at great depth
ii) at the level of footing
iii) at ground surface, Take, Nc=32.36, Nt=18.58 and Nr=15.7. Use Terzaghi's theory.
8 M

7 (a) Explain i) Immediate settlements ii) Primary consolidation settlements and iii) Secondary consolidation settlements.
6 M
7 (b) Estimate the immediate settlement of a footing of size 2m×3m resting at a depth of 1.5m in a sandy soil whose compression modulus is 10N/mm2. Footing transmits a pressure of 200kN/m2. Take μ=0.3 and influence factor as 1.06.
6 M
7 (c) The following results were obtained from a plate load test conducted on dry sand stratum using a square plate of size 0.3m
Determine the settlement of square footing or width 1.5m, under a load intensity of 120 kN/m2.
8 M

8 (a) Explain the factors influencing the selection of depth of a foundation.
6 M
8 (b) Write a note on selection of foundation based on soil stratification and load carried.
8 M
8 (c) Explain the classification of pile foundation.
6 M

More question papers from Geotechnical Engineering 2