## Geotechnical Engineering - 2 - Dec 2014

### Civil Engineering (Semester 6)

TOTAL MARKS:

TOTAL TIME: HOURS

**1 (a)** Describe Culmann's method for the stability analysis of homogeneous slopes.
What are its limitation ?(7 marks)
**1 (b)** A new canal is excavated to a depth of 5m below ground level through a soil
having the following characteristics: c= 14Kn/m^{2}, ϕ=15°, e=0.8 and G=2.70. The slope of banks is 1in 1. Calculate the factor of safety with respect to cohesion
when the canal runs full. If it is suddenly and completely emptied, what will be
the factor of safety?(7 marks)
**2 (a)** A retaining wall 9 m high retains a cohesionless soil, with an angle of internal Friction 33°. The surface is level with the top of the wall. The weight of the top 3 m of the fill is 21 kN/m^{3} . Find the magnitude and point of application of the resultant active thrust.(7 marks)
**2 (b)** Discuss the various landslides remedial measures.(7 marks)
**2 (c)** Determine the safe bearing capacity of a strip footing 1.5m wide and 1.5m depth
resting on a dry sand bed. Consider (γ_{sand}=18 kN/m^{2} and bearing capacity factors N_{c}35.5, N_{q}=23.2, N_{γ}=22.0, corresponding to ϕ=38° and factor of safety=3)(7 marks)
**3 (a)** State functions of foundation. State the causes of failure of foundation. Explain
any one method of improving bearing capacity of soil.(7 marks)
**3 (b)** Differentiate between finite and infinite slopes.(7 marks)
**3 (c)** Enlist factor affecting the bearing capacity and explain any two in detail.(7 marks)
**3 (d)** What is a stability number? What is its utility in the analysis of stability of
Slopes?(7 marks)
**4 (a)** What is Coulomb's wedge theory? Compare Rankine's theory and Coulomb's
Theory.(7 marks)
**4 (b)** Describe 'Negative skin friction'(7 marks)
**4 (c)** Explain Swedish circle method of stability analysis.(7 marks)
**4 (d)** What are the different types of earth pressure? Give examples.(7 marks)
**5 (a)** What is pressure bulb? Explain its use.(7 marks)
**5 (b)** Discuss the Electric Resistivity Method for sub soil Investigation.(7 marks)
**5 (c)** Elaborate the conditions where a pile foundation is more suitable than a shallow
Foundation.(7 marks)
**5 (d)** Differentiate between General shear failure and local shear failure with neat
Sketch.(7 marks)