What is flow net in soil mechanics?

how to draw a flow net

Before delving into these solution techniques, however, we will establish a few key conditions necessary to comprehend two-dimensional flow. Of course that macro only plots the head lines, as it is the head that follows the Laplace’s equation.

  • Emphasis is placed on the need for stochastic analysis of water flow.
  • An equivalent amount of flow is passing through each streamtube , therefore narrow streamtubes are located where there is more flow.
  • Since flow lines are normal to equipotential lines, there can be no flow across flow lines.
  • Flow lines are always at 90 degrees to the equal potential lines.

In this article, we are going to focus on flownet sketching. 15 illustrates equilibrium conditions in a column of soil. The left-hand tank contains water and is connected to the right-hand tank containing soil and water. When the water level is the same in both tanks. There will be no flow of water through the soil. The procedure is continued until the last flow line is formed.

3. Numerical solutions (approximate solutions)

Learn more about this topic, civil-engineering and related others by exploring similar questions and additional content below. The sizes of the squares should change gradually; transitions are smooth and the curved paths should be roughly elliptical or parabolic in shape. Phreatic line is a seepage line as the line within a dam section below which there are positive hydrostatic pressures in the dam. The hydrostatic pressure on the phreatic line itself is atmospheric. Draw a trial flow line ABC adjacent to boundary line. The line must be at right angles to the upstream and downstream beds.

  • Mathematically, the process of constructing a flow net consists of contouring the two harmonic or analytic functions of potential and stream function.
  • Figures 23 and 24 show the results of water drawdown analyses that were carried out using the SEEP/W and PLAXFLOW algorithms, respectively .
  • Another example of flownet are shown in Figures 3.
  • The piles have a center-to-center spacing of 1200 mm.

This line must consist of squares and satisfy the boundary conditions otherwise, the first flow line has to be repositioned and the whole procedure is repeated. The following steps in general how to draw a flow net can be adopted while constructing a flow net by geographical method.The boundary between soil and water is an equipotential line. Draw their V-I characteristics and explain them?

Groundwater Control: Exclusion Techniques

A Flow net is a graphical representation of flow of water through a soil mass. It is a curvilinear net formed by the combination of flow lines and equipotential lines. Properties and application of flow net are explained in this article.

  • In addition, general guidelines are provided for using the methodologies for specific types of analysis, such as transient-state flow caused by water drawdown and flow in unsaturated media.
  • This is also often referred to as piping failure (Fig. 20).
  • Need a deep-dive on the concept behind this application?
  • I need to develop a flow net diagram to solve a finite difference 2D seepage problem, using excel.