Geotechnical Engineering

17 Dec Geotechnical Engineering

how to draw a flow net

Hover over the first shape you placed to see the four direction arrows. Click on one of the shapes, then select a shape to add and connect it in that direction. Click on a rectangle in the General shape library to add it the drawing canvas.

  • In a matter of moments, the chart is going to be displayed in the main window along with the value of the shape factor and the critical point .
  • 2.9b, and the sketching procedure for the flow net is illustrated in Figs c, d, e and f of Fig.
  • Two equipotential lines never cross each other.
  • This method only for a practical method of drawing a flow net for a particular set of boundaries.

The accuracy of the computation of hydraulic quantities, such as discharge and pore water pressure, does not depend much on the exactness of the flow net. From the drawn flow net, Nf and Nd can be easily counted, and hence, the seepage discharge can be easily computed by using Eqn. The equation is used in the construction of flow net. If you are at an office or shared network, you can ask the network administrator to run a scan across the network looking for misconfigured or infected devices. Appropriate data-driven line width settings depend on your project coordinate reference system as well as the value range of the flow data.

It engages, enlightens, and empowers engineers through interesting, informative, and inspirational content. Calculate the transmissivity, storativity and hydraulic conductivity using methods and references listed in Subsection 6.7, Aquifer Data Collection Methods. Draw the first flow line and hence establish the first flow channel. SEEP2D can be used for either confined or unconfined steady state flow models. For unconfined models, both saturated and unsaturated flow is simulated. The phreatic surface can be displayed by plotting the contour line at where pressure head equals zero. First of all, smooth curves representing the flow lines that meet the specified requirements are first marked.

The space formed between two flow lines and two equipotential lines is called a flow field. Flow lines represent the path of flow along which the water will seep through the soil. Equipotential lines are formed by connecting the points of equal total head. Damnasht is a small-sized hydraulics application whose main purpose is to aid individuals in drawing flow nets for sheet piles, as the name hints at. As you can see, virtual layers and geometry generators are a powerful combination. If you encounter performance problems with the virtual layer, it’s always possible to make it permanent by exporting it to a file. This will speed up any further visualization or analysis steps.

Question: How Can We Draw Flow Net

In the template manager, enter a filename for your flow chart, ensure Blank Diagram is selected, then click Create. If you can provide the mathematics I could help with the programming with excel VBA. I have solved flownets before but you make it sound so complex in this case, so I’m thinking you are doing something different than we did in soils classes. There was a finite diff program meant for exactly that i remember doing a homework assignment for. I can imagine in excel this is replicatable, because your lines intersect orthogonally….

This paper shows how to use spreadsheet programmes for desktop computers to construct flownets. The seepage of water is governed by a Laplace- type partial differential equation for the potential head of water, which is solved approximately using finite difference methods. In a previous paper, Smyrell showed how to solve such a finite difference equation using spreadsheet methods, and applied it to torsional stiffness. For a seepage problem, the area of ground considered is divided into a square grid, and cells in the spreadsheet are allocated to each node point of the grid.

how to draw a flow net

Enter the email address you signed up with and we’ll email you a reset link. Since the method includes trial and error proceedings; a lot of practice is required for achieving accurate results. Export as a URL to encode your entire diagram in a URL.

Draw A Flow Net For The Weir Shown In Figure

Drag a shape from the shape library and hover over an existing shape until you can see the four direction arrows. Move over one of these direction arrows, and drop the shape you have dragged. It will be added to the drawing canvas and connected in that direction.

how to draw a flow net

Add more shapes – Use one of the following methods to add extra shapes to represent the next steps in your process. Add the first step – Use one of the following methods to add a rectangle to the drawing canvas. Rectangles represent the steps in your process. I used finite difference method the concept of which can be easily found in Google search. Applied mirror, impermissive and constant boundary conditions according to dam elements.

Computer groundwater models are based on the geologic and hydrologic field data collected during drilling, geotechnical sample analysis and aquifer testing. Further, the computer models must be continually adjusted and calibrated based on additional information obtained throughout the project cycle.

For The Weir Shown In Figure 8 21, Calculate The Seepage In The

Double-click on an empty area on the drawing canvas and select a rectangle shape. Follow this tutorial to create and style a basic flow chart and learn to use the editor. Flow charts let you visually describe a process or system. The shapes and very short labels let readers quickly understand what they need to do. The uplift pressure at any point within the soil mass can be found using the undermentioned formula.

Note that the equation is for laminar flow through porous media. Flow through fractured rock may require a different approach. If the fractured rock is hydraulically equivalent to a porous medium, the above equation may be used. If this condition is not fulfilled, describe the flow in relation to individual fractures. Beneath the dam the outermost flow line will be parallel to the surface of the impermeable layer. Project the equipotentials and repeat the procedure until the flow net is completed.

how to draw a flow net

The next step was the geographic visualization of the flow data and this is where QGIS comes into play. If you’ve been following my posts, you’ll no doubt have seen quite a few flow maps on this blog. This tutorial brings together many different elements to show you exactly how to create a flow map from scratch. It’s the result of a collaboration with Hans-Jörg Stark from Switzerland who collected the data.

Damnasht 3 2

It must be ensured that the equipotential lines are drawn such that the fields form approximate curvilinear squares. First identify the hydraulic boundary conditions. 8.3, the upstream bed level GDA represents 100% potential line and the downstream bed level CFJ, 0% potential line. The long flow line is indicated by the impervious stratum NP. Groundwater modeling may be done manually by using a calculator or spreadsheet and then creating a graphical depiction of the data using flow nets. Manual groundwater modeling methods may be useful for creating preliminary site conceptual models intended to depict aquifer characteristics and the initial contaminant plume extent. A variety of options are provided in GMS for displaying SEEP2D results.

  • The accuracy of the computation of hydraulic quantities, such as discharge and pore water pressure, does not depend much on the exactness of the flow net.
  • If the flow fields in the last flow channel are inconsistent with the actual boundary conditions, the whole procedure is repeated after taking a new trial flow line.
  • Drag one of the waypoints into a new position.
  • The space formed between two flow lines and two equipotential lines is called a flow field.
  • The phreatic line must start from B and not from C.

Other sides of the squares are set equal to the widths as determined above. Irregularities are smoothed out, and the next flow line DF is drawn joining these bases. While sketching the flow line, care should be taken to make flow fields as approximate squares throughout. With compasses determine the position of the next flow line; draw this line as a smooth curve and complete the squares in the flow channel formed. Project the equipotentials beyond the first flow channel, which gives an indication of the size of the squares in the next flow channel.

Civil Engineering

The flow line and equipotential lines should be orthogonal and form approximate squares. Where HL is the total hydraulic head causing flow, and is equal to the difference of the upstream and the downstream heads. The horizontal and vertical component of the hydraulic gradient are, respectively. As an example, suppose that it is necessary to draw the flow net for the conditions shown in Fig. The boundary conditions for this problem are shown in Fig.

  • Groundwater follows the path of steepest groundwater gradient.
  • If you encounter performance problems with the virtual layer, it’s always possible to make it permanent by exporting it to a file.
  • Activate your 30 day free trial to continue reading.
  • Internal erosion is the formation of voids within a soil caused by the removal of material by seepage.
  • Differentiate among progressive die, compound die and combination die.
  • Some of the squares may, however, be quite irregular.

Groundwater follows the path of steepest groundwater gradient. At a site where the aquifer formation is isotropic and porous, the steepest groundwater gradient is the shortest path between equipotential lines. The shortest path is perpendicular to the equipotential lines. Draw flow lines such that the flow is equally divided between adjacent lines.

What Are Uses Of Flow Net Mcq?

To practice all areas of Geotechnical Engineering, here is complete set of 1000+ Multiple Choice Questions and Answers. The seepage medium can be replaced by ____________electric model having the same geometric shape. Groundwater modeling is also used to predict contaminant plume movement into the future or to predict the aquifer and plume response to remedial activities. Which of the following statements about Earth’s living systems is true? Corals are unique in that they are affected not only by changes in the water but also by changes in the atmosphere. Corals are typical of most other marine organisms in that they live best in water that is clear and warm but not hot. Corals are unique in that they are affected not only by changes to water and atmosphere but also by changes to other living things.

Geotech Engineer 101

The method consists of filling the flow area with stream and equipotential lines, which are everywhere perpendicular to each other, how to draw a flow net making a curvilinear grid. Then, the equipotential lines are drawn such that they cut or intersect the flow lines at right angles.