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Geotechnical Engineering Interview Questions and Answers for Experienced people on “Well Hydraulics – Recuperation Test”.
1. The pumping-in test was devised by _________
a) U.S. Bureau of soil and PRA
b) U.S. Bureau of reclamation
c) Indian standard of Bureau
d) None of the mentioned
Answer: b
Clarification: The U.S. bureau of Reclamation (Earth Manual, 1960) has devised two types of pumping-in test.
2. The type of hydraulics of flows towards open well is __________
a) Radial flow
b) Bottom flow
c) Adjacent flow
d) All of the mentioned
Answer: a
Clarification: If the well is open, radial flow takes place all around the well and there is no flow from the bottom of the well.
3. The discharge of an open well can be determined by, which of the following method?
a) Constant head test
b) Falling head test
c) Recuperation test
d) None of the mentioned
Answer: c
Clarification: In the recuperation test, water level can be depressed to any level and the discharge from the well can be calculated.
4. Which of the following well, does not penetrate to the full depth of an aquifer?
a) Fully penetrating artesian gravity wall
b) Partially penetrating artesian wall
c) Partially penetrating artesian gravity wall
d) All of the mentioned
Answer: b
Clarification: A partially penetrating artesian well is the one in which the well screen does not penetrate to the full depth of the confined aquifer. Such wells extend only partly through the water bearing stratum.
5. In Recuperation test, the expression (K/A ) is known as ___________
a) Specific yield and Specific capacity
b) Coefficient of permeability
c) None of the mentioned
d) All of the mentioned
Answer: a
Clarification: K/A is known as the specific yield or specific capacity of an open well, in cubic meter per hour per square meter of the area through which water percolates.
6. For fine-grained soil,the value of K/A as specified by Marrio is _________
a) 1.00
b) 0.50
c) 0.25
d) 2.00
Answer: c
Clarification: For fine-grained type of soil, the value of K/A is 0.25 cubic meter per hour, per sq. m of the area under 1m depression head.
7. When two wells, situated near each other is discharged,the total discharge will __________
a) Increases
b) Decreases
c) Remains the same
d) None of the mentioned
Answer: b
Clarification: When two wells are discharged, their drawdown curves intersect within their radii of zero drawdown. Thus the total discharge is increased.
8. Volume of water dv entering the well, when the head recuperates by dh is ___________
a) dV=A/dh
b) dV=A.dh
c) dV=Khdt
d) dV=K.A
Answer: b
Clarification: Volume of water entering the well, when the head recuperates by dh is given by the equation: dV=Adh
Where, A=cross-sectional area of the well at its bottom.
9. Which of the following flow is less efficient than radial flow?
a) Bottom flow
b) Spherical flow
c) Turbulent flow
d) Linear flow
Answer: b
Clarification: The discharge of spherical flow qs is given by, qs/q =2.3(r/b) log10 1000
Let r =8cm =0.08 m
R/r =1000; b=16 m
qS/q =2.3(0.08/16) log10 1000
qS/q = 1/30
This shows that the spherical flow is much less efficient than the radial flow.
10. An open well has relatively larger diameter at __________
a) Base
b) Middle
c) Top
d) Near the bottom
Answer: b
Clarification: As the velocity of water is larger at the base, the width of base widens up and its diameter increases.
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