1. The bearing capacity of a single pile in clay is mainly due to _________
a) Friction
b) Shear strength of soil
c) Allowable load
d) Ultimate load
Explanation: The bearing capacity of single pile in clay is mainly due to friction, and the friction and the point bearing resistance may be negligible
2. The downward drag acting on a pile due to the movement of the surrounding is called ________
a) Skin friction
b) Negative skin friction
c) Frictional force
d) None of the mentioned
Explanation: Negative skin friction is downward drag acting on a pile due to the downward movement of the surrounding compressible soil relative to the pile.
3. The area of the pile group along the failure surface is equal to __________
a) Perimeter × Area of cross section
b) Breadth × Length
c) Perimeter × Length
d) Perimeter/area of cross section
Explanation: The area of the pile group, along failure surface is approximately equal to the perimeter P of the pile group multiplied by the length L of the pile.
4. The pile spacing of each pile is taken as __________ diameter of the pile.
a) Four
b) Five
c) Three
d) Ten
Explanation: A spacing of three times the diameter of piles is commonly selected as trial spacing between the piles and checked against the criterion that the resistance Qs obtained.
5. The settlement of a group of friction piles can be computed on the assumption that ________
a) Clay is incompressible
b) Pile below the lower level is ignored
c) Bearing resistance is zero
d) None of the mentioned
Explanation: As a rough approximation, the settlement of a group of friction piles can be computed on the assumptions that the clay contained between the top of piles is incompressible.
6. The equation used for determining the bearing capacity of a group of friction piles is __________
a) Qup = Rf + Rp
b) Qug = n Qup . ηg
c) Qug = n Qup / ηg
d) None of the mentioned
Explanation: A method of estimating the bearing capacity of a group of friction piles is to multiply the quantity nQup by a reduction factor called the efficiency of pile group.
Qug = n Qup . ηg.
7.When the under-reamed pile has only one bulb, it is called _________
a) Multi-under reamed pile
b) Single-under reamed pile
c) Unique-under reamed pile
d) All of the mentioned
Explanation: When the pile has only one bulb, it is known as single-under reamed pile, while the pile with more than one bulb is known as multi-under reamed pile.
8. The diameter of the under-reamed pile is kept equal to _______ times the diameter of pile steam.
a) 4
b) 5
c) 2.5
d) 2
Explanation: Generally the diameter of the under-reamed pile bulb is kept equal to 2.5 times the diameter of pile steam. However, it may vary from 2 to 3 times the stem diameter of pile steam.
9. Under-reamed pile foundation is most suitable for ___________ type of condition.
a) Seasonal moisture change
b) Dry conditioned soil
c) Cohesive type of soil
d) All of the mentioned
Explanation: The under-reamed pile foundation find application in widely varying situations in a type of soils where foundation are required to laid on undesirable effect of seasonal moisture change as in expansive soils.
10. The load carrying capacity of a under-reamed pile may be determined by _________
a) Safe load test
b) Penetration test
c) Pile load test
d) Cyclic load test
Explanation: The load carrying capacity of an under-reamed pile may be determined from safe load test, in the absence of actual test.