Ezigrade (version 2)

General Information on Ezigrade

 
Ezigrade's design is based upon our generic civil engineering software called CDS. We have been working on the user interface and general design concepts so that you don't need a degree in Civil Engineering to operate our software. Where possible we try to hide the low level stuff to not overload the operator. At the same time we have kept the ability to work on the base model etc ; so that "tricky" job is do-able. Any Ezigrade job can be opened within CDS and vise-versa to make our software more versatile.
 
Normally when grading etc; Ezigrade sets all the surfaces automatically. If you need to set your own parameters you can click on the Contour manual and drill down to the appropriate menu item. For more involved operations there is the option to open the job back in CDS; which has a myriad of different options.
 
To define any sort of job, we need a number of points. A point is simply a position in space which is defined by an Easting and a Northing value as well as a Natural Surface height. If we do a design we also set another field called "Design Height" that represents where the planned surface should lie. These points can also obtain extra information such as codes, descriptions and layers etc. All these points are stored internally in a database. Ezigrade contains a number of basic routines to manipulate these points. Look for the "Points" panel on the left of the screen.
 
Also our generic program CDS does allow you to access and manipulate these points directly. So if you need to work at the individual point level, you can open the Ezigrade job up directly in CDS. ie In CDS do the File - Open procedure. However you can't open the job simultanously in CDS and Ezigrade. From Ezigrade - go to the File -> Close and Reopen in CDS menu item. CDS has a similar routine to go back to Ezigrade. In CDS you can do things like manipulate an individual point, raise and lower a series of points. Do transformation routines to convert from one system like UTM to another such as State Plane etc. Create Civil Designs on top of your Ezigrade design etc.
 
In Ezigrade we can have a number of different surface types:
  • a Natural surface which is the existing height.
  • a Design surface which is what we want to achieve
  • a Cut/Fill surface which shows whether we need to add dirt at a point or remove some dirt.
  • a Ponding surface which shows position where water sits on the ground and how deep it would be.
 
One way of representing a surface from a series of points is draw a set of interconnected triangles that define the surface. Then if we wish to know the height at a position which doesn't contain an existing point then we can simply interpolate mathematically a height that lies upon the triangle. You will often find these surfaces called TIN Triangular Irregular Network. They work for both irregular points or points in a grid. For our more knowledgeable clients; you may know what a breakline is. A breakline forces the triangles to lie along a certain line. This is important for representing features like creeks etc. Normally for flat agricultural situations; breaklines are not needed. Ezigrade sets some breaklines automatically when we are working with structures such as outles, drains and banks. Ezigrade itself has no functions at present to manipulate breaklines. However if you do need them you can drop back into CDS and set them there.
 
To represent on the screen what a surface looks like we use things called contours. They are simply lines that join points at the same height. Water runs perpendicular to a contour line. If you move the cursor around the screen the current cursor height is shown in the status bar at the bottom of the screen This allows you to visualize which way the water will run.
 
We often wish to split our complete job into smaller sub-surfaces. We call these smaller pieces - sections. Each of these sections is represent by a series of closed lines that we call links. Each link has two nodes. Ezigrade allows you to click on the end of a field link and drag it. All the field links that share this node are moved. Hence neighboring sections are all modified.
 
When designing the grading for a section; we have a number of parameters that we can change. Firstly we can define the type of design. We can have
 
  • a plane design. This is a flat plane - very handy for irrigated area's.
  • a variable design - where we specify the minimum and maximum grades that are allowed to make the water run as we desire. We can also specify a smoothing parameter to eliminate sudden change of grades.
  • design that eliminates any ponding - water can flow from the field in any direction. Here we simply need to specify a minimum and maximum grade and a smoothing factor. Typically this will give the lowest volumes. This design would be most beneficial in dry area's. Australian melon holes are particularly suitable for this design.
 
We can also specify a grading direction specific to each field. Look for the grading edit box.
 

Tell me more about Outlets, Drains and Banks:

 
These are all linear features that either carry water or stop water flowing.
 
Outlets and Drains both carry water. They both need you to initially sketch in an alignment.
 
Ezigrade started with just drains. They are very much user definable. You can best fit a profile along the drain or you can design it manually. You can also define individual sections. The drain has a seperate profile view to see exactly how the profile varies along the alignment. Ezigrade can also report on the drain volumes etc. The triangle based grading routines know of the existance of the Drain and adjust the grading appropriately.
 
Outlets however only allow you to design the alignment. The profiles and sections are designed automatically by Ezigrade. It is designed to integrate into the triangle based grading routines. An outlet is easier to design but gives you less user control.
 
Banks are designed to stop water flowing across a surface. However the alignment design is automated. You often want banks to have a constantly changing height. Zero grade will follow a contour line, while a non-zero grade will follow the surface to give a constant profile. Like the drain the user can define the top of the bank and how the sections look across a bank.
 

Grid

 
Ezigrade also includes a feature called a Grid. This is used when creating a number of different types of output reports. Traditionally users would like the cut and fill or volumes set out in a regular array. This dates back to the day when users did there design with spreadsheet type programs. Modern GPS systems have outdated this procedure. Ezigrade allows you define a grid and move it around using grip points. You can set grid parameters exactly by typing in the appropriate values in the Grid panel at the left of the screen.
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