Engineering Questions with Answers - Multiple Choice Questions
Load Carrying Capacity of Piles
1 - Question
The maximum load which can be carried by a pile is defined as its __________
a) Ultimate load carrying capacity
b) Ultimate bearing resistance
c) Ultimate bearing capacity
d) All of the mentioned
View Answer
Answer: d
Explanation: The ultimate load carrying capacity, or ultimate bearing resistance or ultimate bearing capacity Q up is defined as the maximum load which can be carried by a pile and at which the pile continues to sink without further increase of load.
2 - Question
The allowable load which the pile can carry safely is determined on the basis of ________
a) Factor of safety
b) Load test
c) Stability of the pile foundation
d) All of the mentioned
View Answer
Answer: c
Explanation: The allowable load Qa is the safe load which the pile can carry safely and is determined on the basis of: i) overall stability of the pile-foundation ii) the permissible settlement iii) ultimate bearing resistance divided by factor of safety.
3 - Question
The load carrying capacity of a pile can be determined by which of the following methods?
a) Dynamic formulae
b) Static formulae
c) Plate load test
d) All of the mentioned
View Answer
Answer: d
Explanation: The load carrying capacity of a pile can be determined by the following methods: i) Penetration tests ii) Dynamic formulae iii) Static formulae iv) Plate load test.
4 - Question
Which of the following are some of the commonly used dynamic formula?
a) Engineers News formula and Hiley’s formula
b) Static formula
c) None of the mentioned
d) All of the mentioned
View Answer
Answer: a
Explanation: The Engineers News formula as proposed by Wellington and Hiley’s formula given by the original expression of Hiley are the commonly used dynamic formula.
5 - Question
When a pile hammer hits the pile, the total driving energy is equal to _________
a) Weight of hammer times the height of drop
b) Weight of the ram time times the height of the stroke
c) Sum of the impact of the ram
d) Sum of the impact of ram plus the energy delivered by explosion
View Answer
Answer: a
Explanation: When a pile hammer hits the pile, the total driving energy is equal to the weight of hammer the height of drop or stroke.
6 - Question
Dynamic formulae are best suited for _________ type of soil.
a) Fine grained soil
b) Coarse grained soil
c) Cohesive soil
d) None of the mentioned
View Answer
Answer: b
Explanation: Dynamic formulae are best suited to coarse grained soils for which the shear strength is independent of rate of loading.
7 - Question
Dynamic formula does not indicate about _________
a) Temporary change in soil structure and Future settlement
b) Allowable load
c) None of the mentioned
d) All of the mentioned
View Answer
Answer: a
Explanation: A disadvantage of a dynamic formula is that it gives no indication about the reduced bearing future settlement or temporary changes in soil structure.
8 - Question
The dynamic formula is valueless for which of the following type of soil?
a) Loose sand
b) Saturated soil
c) Clay soil
d) Compacted soil
View Answer
Answer: c
Explanation: For clays, the dynamic formulae are valueless because the skin friction developed in clay during driving is very much less than which occurs after a period of time.
9 - Question
In dynamic formulae what are the energy losses, that is not accounted?
a) Energy Loss due to vibration and Energy loss due to heat
b) Frictional loss
c) None of the mentioned
d) All of the mentioned
View Answer
Answer: a
Explanation: In dynamic formulae, the energy loss due to vibrations, heat and damage to dolly or packaging are not taken into account.
10 - Question
The greater objection to any of the pile driving formulae is _________
a) Uncertainty in relation between dynamic and static resistance
b) Shear strength of the soil
c) Uncertainty in the allowable pressure
d) None of the mentioned
View Answer
Answer: a
Explanation: The greater objection to any of the pile driving formulae is the uncertainty about the relationship between the dynamic and static resistance to soil.
11 - Question
The static formula is based on the assumption that the ultimate bearing capacity Qup is equal to ___________
a) Rf + Qa
b) Rf + Rp
c) As + Ap
d) Q up / F
View Answer
Answer: b
Explanation: The static formulae are based on the assumption that the ultimate bearing capacity Qup of a pile is the sum of the total ultimate skin friction Rf and total ultimate point or end bearing resistance Rp:
Qup = Rf + Rp.