Engineering Questions with Answers - Multiple Choice Questions
Seepage Analysis – Phreatic Line of an Earth Dam
1 - Question
What are the essentials, required to draw a flow net?
a) Top Flow and Phreatic line
b) Stream line
c) None of the mentioned
d) All of the mentioned
View Answer
Explanation: In order to draw the flow net, it is first essential to find out the location and shape of the phreatic line and top flow line separating the saturated and unsaturated zones.
2 - Question
The phreatic line can be located by which of the following method?
a) Graphical method
b) Experimental method
c) Analytical method
d) All of the mentioned
View Answer
Explanation: As suggested by casagrande, the phreatic line can be located by graphical, experimental and analytical methods.
3 - Question
Kozney’s top flow lines is called as ____________
a) Basic and Base parabola
b) Simple parabola
c) None of the mentioned
d) All of the mentioned
View Answer
Explanation: Kozney’s solution for flow of water consists of a family of confocal parabola s representing the flow lines. Hence kozney’s top flow line is called the basic or base parabola.
4 - Question
For the water flowing above an impervious, infinite, horizontal plane. The net flow is given by ___________
a) Casagrande
b) Kozney
c) Forchheimer
d) Darcy
View Answer
Explanation: In 1938, kozney analytically derived a flow net for the case of water flowing above an impervious, infinite, horizontal plane which at a certain place becomes permeable.
5 - Question
What is the line within a dam section, below which there are positive hydrostatic pressures?
a) Phreatic and Seepage line
b) Equipotential line
c) None of the mentioned
d) All of the mentioned
View Answer
Explanation: The phreatic line or seepage line is the line within a dam section below which there are hydrostatic pressures in the dam. The hydrostatic pressure below on the phreatic line itself is atmospheric.
6 - Question
The flow lines and equipotential proposed by Kozney is in the shape of ____________
a) Hyperbola
b) Ellipse
c) Parabola
d) Circle
View Answer
Explanation: According to flow net derived by Kozney, the flow lines and equipotential consist of the shape of parabola.
7 - Question
The analytical solution of schaffernak and Van Iterson gave result only for slopes, having __________
a) α>30°
b) α<30°
c) α>60°
d) α<60°
View Answer
Explanation: The analytical solution of schaffernak and van iterson provided result, as long as slope is gentle i.e., α<30°. For steeper slopes, the deviation form correct values increases rapidly beyond tolerable limits.
8 - Question
What kind of method was suggested by Casagrande, for determining the phreatic line?
a) Experimental method
b) Analytical method
c) Graphical method
d) All of the mentioned
View Answer
Explanation: Graphical method was used by Casagrande for the determination of the phreatic line using flow net.