Engineering Questions with Answers - Multiple Choice Questions
Well Curb, Cutting Edge, Steining and Bottom Plug
1 - Question
The well curb is designed for which of the following purpose?
a) For avoiding skin friction
b) Supporting the weight of well
c) For designing the well
d) All of the mentioned
View Answer
Answer: b
Explanation: The well curb is designed for supporting the weight of the well with well partial support at the bottom of the cutting edge.
2 - Question
Which of the following can be assumed for design purpose of well curb?
a) Three point support of cutting edge
b) Boulders
c) Skin friction
d) Steining
View Answer
Answer: a
Explanation: A three-point support of the cutting edge resting on a log may be assumed for design purposes of well curb.
3 - Question
An effective well curb should withstand ___________
a) Maximum stress
b) Stress due to sand blows
c) Its own weight
d) Blasting
View Answer
Answer: b
Explanation: The well curb has to withstand stress due to sand blows, as well as due to light blasting required when boulder obstructs the sinking of well.
4 - Question
The cutting edge should be provided with an angle of __________
a) 45°
b) 60°
c) 90°
d) 30°
View Answer
Answer: d
Explanation: The cutting edge should have as sharp an angle of 30° practicable for knifing into the soil without making it too weak to resist the various stresses induced.
5 - Question
A sharp vertical edge for the well is provided at _________
a) Inner Face of the well
b) Out of the well
c) Outside face of the caisson
d) All of the mentioned
View Answer
Answer: c
Explanation: A sharp vertical edge or cutting edge should be provided along the outside face of the caisson or open well.
6 - Question
At a given depth, the skin friction of the well is equal to __________
a) Diameter of well
b) μ times the lateral earth pressure
c) Stress condition
d) All of the mentioned
View Answer
Answer: b
Explanation: The unit skin friction increases with depth, and at a given depth, the skin friction is equal to the coefficient of friction μ times the lateral earth pressure.
7 - Question
For loose sand, the value of skin friction is between ________
a) 0.73-2.93
b) 4.9-19.5
c) 1.22-3.42
d) 3.42-6.84
View Answer
Answer: c
Explanation: For the purpose of design, the values of skin friction given by Terazaghi and peck may be used:
Silt and soft clay: 0.73-2.93 t/m2
Very stiff clay: 4.9-19.5 t/m2
Loose sand: 1.22-3.42 t/m2
Dense sand: 3.42-6.84 t/m2
Dense gravel: 4.9 -9.4 t/m2.
8 - Question
Frictional resistance developed during the sinking the well depends on __________
a) Roughness of the surface of contact
b) Diameter of the well
c) Type of soil
d) Lateral earth pressure
View Answer
Answer: a
Explanation: Frictional resistance depends on the roughness of the surface of contact. For example, a smoothly plastered well steining surface is said to reduce frictional resistance.
9 - Question
The skin friction developed in San Francisco Oakland Bay Bridge, was reduced by, which of the following methods?
a) By introducing special equipment
b) By coating smooth oil surface
c) By decreasing the stress developed
d) All of the mentioned
View Answer
Answer: b
Explanation: In order to reduce the skin friction on the in San Francisco Oakland Bay Bridge, a coating which gave a smooth oily surface that was estimated to reduce the friction between the concrete and fairly clay by 40 %.
10 - Question
The bottom plug is designed in _________ shape.
a) Rectangular
b) Mushroom
c) Bowl-shaped
d) Circular
View Answer
Answer: c
Explanation: The bottom-plug is made in bowl-shaped so as to have inverted arch actions.