The upstream portion of the line of seepage is drawn from point B to join in gradually with the basic parabola at point C.

Details. The flow tubes formed by flow line and equipotential line should be approximately square in shape. Similarly, the stream line is defined as the path along which individual particle of water seeps … Flow Net for an Earth Dam Top Flow Line or Phreatic Line Flow Line Equipotential Line Field Phreatic Line is a seepage line separating saturated and unsaturated zones 26. The flow line and equipotential line will intersect each other at right angle. Chapitre 10.

Figure 17.14 shows the flow net for the earth dam. The pore pressure u 2 at point b is equal to the vertical distance between points a and b to the scale of the flow net or the dam section.

The seepage line in the body of the dam is such a line below which there is positive hydrostatic pressure.

At point B the flow line must intersect the upstream slope of the dam which is an equipotential line, at right angles. (It is usually easier to start by drawing the flow lines). Equipotential lines are like contour lines on a map which trace lines of equal altitude. downstream side, the water is at the surface level which results in an equipotential line with a total head equal to 0 m. The equipotentials and the stream lines determined by the flow net method are presented in Figure1(Lambe & Whitman, 1979). Flow Nets 1 10.1 Introduction Let us consider a state of plane seepage as for example in the earth dam shown in Figure 1. All intersections between the streamlines and equipotential lines are at right angles. 4). Equipotential Lines. Polynomial approximation of equipotential lines for flow under a dam.

Above the line, there is a zone of capillary saturation. 10. The earth dam …

any flow that may have existed in the capillary zone above the phreatic line was ignored. The first equipotential line (EPL1) intersects the phreatic line at point a and the trial slip surface at point b.

Soil Mechanics Flow Nets page 2 Drainage ... and which has orthogonal equipotential and flow lines.

1 Réseaux d'écoulement . B) Represent Your Choice Of Datum.

The equipotential line represents the contour of equal head or energy or potential. The Casagrande method is used for deriving the phreatic line; the procedure is described as under: Equipotential lines pass through points of equal pressure. Line of Seepage or Prelatic Line in Earthen Dams • Line of Seepage or the Phreatic line of saturation line is defined as the line within the dam section below which there are positive hydrostatic pressure in the dam.

The upstream face of the dam represents 100% equipotential line, when it is covered by the water, at this condition the seepage line should be drawn perpendicular to this face at the junction point. An equipotential line cannot intersect another equipotential line 25.

Equal to Zero. For tailings pond dams., the centerline, or the upgradient boundary of the flow region, is a flow line instead of an equipotential line. The direction of seepage flow is always perpendicular to the equipotential line. Civil Engineering Dams A dam is a barrier that impounds water or underground streams.