Question

Consider the following statements:
Phreatic line in an earth dam is
1. elliptical in shape
2. an equipotential line
3. the top most flow line with zero water pressure
4. approximately a parabola
Which of these statements is/are correct?

• A. 1, 2 and 3
• B. 2, 3 and 4
• C. 3 and 4
• D. 1 alone

Answer 1

The correct option is C 3 and 4

Phreatic line is the top flow line which separates saturated zone from unsaturated zone and below which positive hydrostatic pressure exists in the dam section. Along the phreatic line, the atmospheric pressure exists. It's shape is approximately of a parabola.