GTE II Assignment

MAHATMA GANDHI INSTITUTE OF TECHNOLOGY

Gandipet, HYDERABAD – 500075

DEPARTMENT OF CIVIL ENGINEERING

IiI B.Tech

Geotechnical Engineering – II

Assignment – II

Last date for submission: 18-04-2015

1.    Discuss the assumptions in the Terzaghi’s Bearing Capacity Analysis and explain the stpes involved in the determination of bearing capacity of strip footings.

2.    Explain the following terms.

a.    ultimate bearing capacity

b.    safe bearing capacity

c.    allowable bearing pressure

d.    safe bearing pressure

3.    A strip footing, 1.5 m wide, rests on the surface of a dry cohesionless soil  having φ = 20°

and γ = 19 kN/m³. If the water table rises temporarily to the surface due to flooding, calculate the percentage reduction in the ultimate bearing capacity of the soil.

Assume Nγ = 5.0.    (Ans: 50%)    

4.    Compute the safe bearing capacity of a continuous footing 1.8 m wide, and located at a depth of 1.2 m below ground level in a soil with unit weight γ = 20 kN/m3, c = 20 kN/m2, and φ = 20°. Assume a factor of safety of 2.5. Terzaghi’s bearing capacity factors for φ = 20° are Nc = 17.7, Nq = 7.4, and Nγ = 5.0, what is the permissible load per metre run of the footing? (Ans: 473.5kN)

5.    Explain the method of conducting plate load test to determine the bearing capacity of soils in shallow foundations.

6.    A group of 16 piles of 50 cm diameter is arranged with a centre to centre spacing of 1.0 m. The piles are 9 m long and are embedded in soft clay with cohesion 30 kN/m2.Bearing resistance may be neglected for the piles—Adhesion factor is 0.6. Determine the ultimate

load capacity of the pile group. (Ans 3780 kN)

7.    With a neat sketch explain the component parts of a well foundation.