a)

b)

a)

b)
a)

b)

03000CE364052001

Correction curves for elastic settlement of Mexitle rectangular
foundations at depth (Fox, 1948)

Compute the net safe bearing pressure of a circular footing 3 m diameter founded in a
deposit of fine sand at a depth of 1.5m below ground surface. Water table occurs a depth
of 3 m below ground level. The unit weight above water table is 18 kN/m3. The average
N value for a depth of 6 m below the base of the footing is 18. Use Teng’s correlation.
The allowable settlement is 25 mm.
Briefly discuss the methods to reduce heave during excavations.
PART 13

Answer any two full questions, each carries 15 marks.
A circular concrete pile of diameter 450 mm is installed in a clay stratum having
undrained shear strength of 100 kPa. Determine the length of the pile needed if the pile
has to carry a load of 420 KN with a factor of safety of 2.5 against shear failure. Take
adhesion factor of 0.6.
Discuss the different types of pile load tests.
A concrete pile, 9m long, was driven by a single acting hammer with rated energy 40 kJ.
The total settlement as recorded for the last 10 blows was 2.5 mm/ blow. Using
Engineering News Record formula, calculate the pile capacity.
A concrete square pile is 16 m long and 410 mm X 410 mm in cross-section. The pile is
fully embedded in sand having unit weight of 17 kN/m? and angle of internal friction
30°. Determine the ultimate load carrying capacity of the pile. Assume Nq= 90; K is one

half of coefficient of passive earth pressure and 6-0.75ന

Page 2 of 3

(10)

(5)

(7)

(8)
(6)

(9)