Monday, February 26, 2018

Surveying Related Ideas

Often times we need to create rectangles to represent existing features that look like rectangles.  To save time surveyors will shoot two points and then in the office convert those two points into rectangles. With lisp we can automate the rectangle creation down to picking two clicked points.

  • This forum post has some lisp code that does just that. Here is a link to a text file with the code extracted in case the forum post goes down.
  • To run the lisp save it to a text file with the extension of .lsp
  • Type Appload at the command line.
  • If you want to run it once, select the file from the upper portion of the Appload dialog box.
  • If you want the lisp to load everytime AutoCAD is run, then add the lisp file to the Startup Suite.


A second desired workflow is to create a point at the intersection of two selected objects, the objects don’t have to intersect. The objects may be arc, line, polyline, lot line, or feature line.


To start open the Point Create Creation Tools.


Then under the second drop down choose the Object/Object option.


Then follow the prompts. This will create a point where the objects intersect. If you want to remove any of the prompts you can change the settings of the Point Creation command using the double down arrow on the right of the Create Points toolbar.

Friday, February 16, 2018

Average Cut and Fill

I have no idea what the Average Cut and Average Fill of a volume surface means or how it should be calculated. It sounds like a made up term from a planner so they can come up with a made up value to judge impacts for a project. Since I don’t have a good explanation of what the average cut or fill is here is one way to do it in Civil 3D.

  1. Create the volume surface.
  2. Go into the Volume Surfaces, Analysis Tab. Change the type to Elevation, the number of Ranges to 2 and then press the down arrow to apply the 2 elevation ranges. image
    1. Change the Ranges to 0 for the Maximum Elevation for the first range and 0 for the minimum elevation for the second line. image
    2. Then create a Surface Legend table for the Elevation Analysis. image
    3. Now take the Cut Area and divide it by the volume of cut and the Fill Area and divide it by the volume of fill. Then you should have average cut/fill numbers. You can find the volume numbers in the volumes dashboard or on the Statistics tab. You can even add the volumes to the table.

    Now I have no idea if this is correct. I did end up with an average number that has the correct units. I can think of numerous other more complicated methods to calculate these values.


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