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03000CE364052001

The following data was obtained in a vertical pile load test on a 400 mm diameter pile

Load (KN) 50 100 1 र 400 1500 1600

| Settlement(mm) | 2.5 | 41 | 63

Plot the load-settlement curve and determine the allowable load as per IS code.
A 20 m deep bored pile has a shaft of 1 m diameter and enlarged base of 2 m diameter in
the lower 1 ൩ depth. The undrained cohesion of soil varies from 100 kN/m? at top to 250
kN/m’ at the base. Determine the safe load (F.S = 2.5.0५ =0.45)
PART C

Answer any two full questions, each carries 20 marks.
List the forces acting on well foundation
A group of nine piles arranged in a square pattern is to be proportioned in a deposit of
soft clay to carry an incoming load of 550 kN. Calculate the settlement of the pile group
by equivalent raft approach if the piles are square with side 300 mm and have a centre to
centre spacing of 500 mm. The thickness of the stratum is 8 m and the piles are
embedded to a length of 5 m in the clay. The properties of the clay are given as: Ysa: = 19
kN/m*, எட்‌ 45% and ടേ 1.5. Ground water table is at the ground surface.
Explain the concept of negative skin friction
A group of 16 piles of 45cm diameter is arranged with a center to center spacing of 1.0m.
The piles are 8m long and are embedded in soft clay with cohesion 3010/13, Adhesion
factor is 0.54. Determine the ultimate load capacity of pile group.
Explain the components of well foundations and its functions with a neat sketch. What
are the different shapes of well foundations?
A single tube circular well foundation of 3.5 m diameter is installed to a depth of 7m
below the scour level in granular soil. The corrected standard penetration value (N value)
in the bearing stratum is 60. Estimate the allowable bearing pressure of the well
foundation.
Explain Terzaghi’s analysis of lateral stability of well foundation.

Describe the methods to correct tilts and shifts during well sinking.

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