250+ TOP MCQs on Under-Reamed Pile Foundations and Answers

Geotechnical Engineering Multiple Choice Questions on “Under-Reamed Pile Foundations”.

1. 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
Answer: b
Clarification: 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.

2. 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
Answer: c
Clarification: 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.

3. 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
Answer: a
Clarification: 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.

4. 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
Answer: a
Clarification: The load carrying capacity of an under-reamed pile may be determined from safe load test, in the absence of actual test.

5. The under-reamed piles are connected by a beam known as ___________
a) Capping beam and Grade beam
b) Reamed beam
c) None of the mentioned
d) All of the mentioned
Answer: a
Clarification: The under-reamed piles are connected by a reinforced concrete beam, known as capping beam or grade beam.

6. The maximum spacing of the under-reamed pile should not normally exceed __________
a) 2 meters
b) 2½ meters
c) 1.5 meters
d) 30 centimeters
Answer: b
Clarification: The maximum spacing of the under-reamed pile should not normally exceed 2½ m as to avoid heavy capping beams.

7. Under reamed piles are normally bored _________ piles.
a) Cast-in-situ piles
b) Pre-cast-piles
c) Steel piles
d) Composite piles
Answer: a
Clarification: Under reamed piles are bored cast-in-situ concrete piles having one or more bulbs formed by enlarging the bore hole.

8. The spacing of the piles in under-reamed pile foundation depends on which of the following factor?
a) Nature of the ground and Type of pile
b) Load acting on the pile
c) None of the mentioned
d) All of the mentioned
Answer: a
Clarification: The spacing of the piles shall be considered in relation to the nature of the ground, the types of pile and the manner in which the pile transfers the load to the ground.

9. The grade beams are designed for a maximum bending moment of _________ if the beams are supported.
a) (wL2)/50
b) (wL2)/30
c) (wL2)
d) None of the mentioned
Answer: a
Clarification: The grade design are designed for a maximum bending moment of (wL2)/50 if the beam are supported during the construction, and for a bending moment of (wL2)/30 if the beams are not supported.

10. The details of the depth of beam and reinforcement required for various loading is provided by_______
a) Indian standard code
b) Central Building Research Institute, Roorkee
c) M.I.T system
d) None of the mentioned
Answer: b
Clarification: Design of grade beam, depth of beam and reinforcement required for various loading is provided by Central Building Research Institute, Roorkee.