Modelling

Alternative Stage Storage Technique – Civil 3D Tables

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UPDATE 2: My new tool complete obsoletes this process.. Stage storage basin tool is available in my free tools package here
https://ceethreedee.com/ceethreedee-tools

UPDATE: Feeling Lazy. Watch the Video.

This deals with basic “basin” stage storage calculations. For more complex stockpiles etc. Read this post here

Download lisp file from this link download COT

UPDATE: instead of using COT.lsp. Try the free “Table Exporter” App from the autodesk exchange from here. Only works in 2015 unfortunately 🙁

It will dump what ever table you select straight to excel though..
exporttable1exporttable3

I see a lot of people still using this outdated tool in Civil 3D for calculating stage storage! For those who calculate stage storages read below!

Please stop using it! Although it is possible to get a relatively accurate result from it. There are a number of problems that I will merely bullet point below.

  • Can only have one contour at each level to get stage storage curve. (although you can sum them together in excel)
  • If contours are not closed this can create errors in the calculation.
  • Multiple islands and “flat areas” (i.e benching) can be easily miscalculated. Who has benching in their designs! :p
  • Higher Intervals reduces accuracy!
  • Not to mention it is cumbersome!

Civil 3D has always had the ability to do accurate stage storages, I will demonstrate below. (*with the assistance of a lisp!)

Download lisp file from this link download COT

1. Create a Volume Surface comparing Water Level or Final Tailings level etc. and your completed design. (Yes you can calculate tailings stages as well!)

2. Drop down elevations in the analysis tab at the intervals you wish to calculate your volumes at. (use Range Interval with Datum)

3. Create a surface legend table that includes “Surface Range volume” and Surface Range 2d area)
SurfaceAreaVolume

4. Copy table to left or right and explode twice, then use the attached lisp routine to convert to an autocad table.

5. Export Table to CSV as shown above and then open in excel. You will need to sum the areas and volumes from the bottom up to get the correct results.

Finished Result, sum up the volumes from the lowest elevation, (so the bottom up). or reverse the order and sum them from the top down..

Elevation (m) Plan Area (m²) Cum. Area (m²) Volume (m³) Cum. Volume (m³)
102 5,872 143,202 280,514 1,432,735
100 5,751 137,330 268,936 1,152,221
98 5,969 131,578 257,244 883,285
96 13,903 125,609 240,933 626,041
94 26,862 111,706 200,242 385,108
92 42,463 84,845 126,689 184,866
90 31,232 42,382 51,424 58,177
88 11,149 11,150 6,752 6,753
86 1 1 1 1

You will notice that unlike the old stage storage tool that can vary in accuracy especially with larger intervals. This method is exactly right down to the triangle.

Comment below if you want to know more

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13 thoughts on “Alternative Stage Storage Technique – Civil 3D Tables”

  3. Pingback: Stage Storage Analysis of Stockpiles/Dam Walls (between two irregular surfaces) | Cee Three Dee

  4. It seems the “Table Exporter” App is only available for 2015 version.

    And I discovered the COT.lsp will crash if you have your table ‘twisted’. I was working with a view twist in my drawing, and a C3D table set to Maintain View Orientation.

     

    But I have a question: how do you convert the depths to elevations? I added “Maximum elevation” to the actual elevation of the bottom of my ponding area (Catchbasin grate elevation).

    And when you say “from the bottom up” I’m confused. But then your finished table is upside-down to what I’m used to doing.

     

     

    1. thats real shame about that table exporter app.. might have to inquire about that one.

      If you change your UCS to the table then i imagine COT.slp will work.

      To convert the depths to elevations, work out what elevation your comparison surface is (the flat water surface). Lets say that elevation is 230 m and the interval you chose for your stage storage is 2m. Remove the entries where depth is < 0 first, these are cut volume above your water level. Then enter your water elevation on the first row, 230 m. Then simply subtract 2m for each row below. It is in reverse of what your used to but still gives you the same answer. You can either sum them from the bottom up. or reverse the order and sum them from the top down.. As long as you sum them from the lowest elevation you will get the answer your looking for. Determing the Elevation

  5. My volume surface gives a volume of 523.49 in the dashboard.

    When I sum up the volumes in Excel I get 528.90.

     

    The 2d Area listed in the dashboard is 2483.86, which matches the area of the polyline that is the boundary of my top of water surface.

    But when I sum up the areas in Excel I get 2537.11.

     

    So yes, I’m confused!

  6. So I renamed Min & Max Elevations to Min & Max DEPTH instead. Depth from top of pond makes sense to me.

    And the actual elevation at each increment = Top of Pond elevation – Max Depth, correct?

     

    But I’m still not getting the right answer. Either for the total volume, or for a specific increment where I have a surface made to check the volume. It may not be off by a whole lot, but enough to say that this pond is or isn’t big enough for a certain flood. And as you say “This method is exactly right down to the triangle.” So I should be getting the same answer as I do with the TIN volume surface at every increment.

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