What is equipotential line?

Summary. An equipotential surface is the collection of points in space that are all at the same potential. Equipotential lines are the two-dimensional representation of equipotential surfaces. Equipotential surfaces are always perpendicular to electric field lines.

What is equipotential line in geotechnical engineering?

The points along the equipotential line will have the equal head, which causes the flow. If we place the piezometer at different points along an equipotential line, the water level will be same. This is the line present in the flow net, and also called as drop line.

What is an equipotential line in hydrology?

An equipotential line, a line of constant head, may be used to form a constant head hydraulic boundary (Fig. 4.12), or specified flow rates may be calculated across the equipotential line and used to specify boundary flows.

What is a line equipotential line and a flow line?

Flow Line: A line along which a water particle moves through a permeable soil medium. (a.k.a. streamline). … Equipotential Lines: A line along which the potential head at all points is equal.

What is equipotential groundwater?

The equipotential lines represent the height of the water table or potentiometric surface above mean sea level or other datum plane. Add flow lines to depict the movement of groundwater at the site. Groundwater follows the path of steepest groundwater gradient.

What are equipotential drops?

The space between two adjacent equipotential lines represents a drop in head. The space between two adjacent equipotential lines is called an equipotential space.

Why are equipotential lines important?

Equipotential lines provide a quantitative way of viewing the electric potential in two dimensions. Every point on a given line is at the same potential.

How do you find flow lines and equipotential lines?

What is phreatic line in earth dam?

From Wikipedia, the free encyclopedia. The top flow line of a saturated soil mass below which seepage takes place, is called the Phreatic line. Hydrostatic pressure acts below the phreatic line whereas atmospheric pressure exists above the phreatic line.

How do you draw an equipotential line?

The equipotential lines can be drawn by making them perpendicular to the electric field lines, if those are known. Note that the potential is greatest (most positive) near the positive charge and least (most negative) near the negative charge.

What are the characteristics of phreatic line?

Phreatic line is also known as the seepage line or saturation line. It is defined as an imaginary line within the dam section, below which there is positive hydrostatic pressure, and above there is negative hydrostatic pressure in the dam section.

What is the significance of phreatic line in the safety analysis of earthen embankment?

The position of the phreatic line influences the stability of the earth dam because of potential piping due to excessive exit gradient and sloughing due to the softening and weakening of the soil mass as if it touches the downstream slope or intersects it.

Which is the recommended shape of seepage line in actual dams according to Casagrande?

This line is called phreatic line or seepage line. The soil is saturated below this line and pressure on this line is atmospheric. Casagrande observed that the shape of this top flow line is close to a parabola for most of its length and deviates from parabola only at the upstream and downstream faces.

Why is it important that the phreatic line does not cross the downstream surface?

Hence the phreatic line should not intersect the downstream slope and it should be a distance greater than capillary rise below the sloping face so that the chances of the sloughing or piping may be nullified.

Why determination of seepage line is required?

The flow of seepage water, below the phreatic line, reduces the effective weight of the soil; as a result shear strength of a soil is reduced due to increased intergranular pressure in earth fill material. In this case, before going directly for derivation, the important features of phreatic line must be known.

What is phreatic line how do you draw it to estimate seepage through earth dam?

The phreatic Line or seepage line is defined as the line within a dam section flow which they are positive hydrostatic pressure in the dam the hydrostag phreatic line graphically: AB is upstream face let it horizontal projection be L. On The Water surface measure a distance BC = 0.32.

What causes the uplift pressure in a dam?

When a dam rests on a porous material, such as sand or gravel, through which water can penetrates, there will be a seepage flow under the dam from the upstream side to the downstream side. Accompanying this flow, there will be an upward pressure acting on the horizontal base of the dam.

What is the purpose of a flow net?

A flow net is a graphical representation of two-dimensional steady-state groundwater flow through aquifers. Construction of a flow net is often used for solving groundwater flow problems where the geometry makes analytical solutions impractical.

What is a phreatic surface?

The term ‘phreatic surface’ indicates the location where the pore water pressure is under atmospheric conditions (i.e. the pressure head is zero). This surface normally coincides with the water table.

What are the different types of earthen dams?

CLASSIFICATION OF EARTHEN DAMS
  • Classification Based Upon the Method of Construction.
  • (i) Rolled-fill earth dams.
  • (ii) Hydraulic fill dams.
  • (i) Homogeneous earth dams.
  • (iii) Diaphragm type earth dam.