Landfill Cap Grading

[sendhil.kumar]

I am familiar with grading a landfill cap using a featureline along the perimeter - when the perimeter is flat. However, grading the landfill cap from an uneven perimeter (varying elevations) is a mess in acheiving accurate 3:1 slopes. Are there any techniques that can be used to achieve this grading? I use AutoCAD Civil 3D 2013. 

Thanks for your help.

[sirjoelsph]

I can feel the pain of the OP here - I used to have to do this kind of grading.  Civil 3D has no good built in way to handle creating a perfect 1:3 slope when the original feature line has any slope itself.  I developed a very manual process when designing a brand new landfill a number of years back in order to get those exact required slopes.  I was luckily doing enough of the 'manual' grading that I eventually got very quick at it.

On a side note - I brought this exact problem up with a programmer at Autodesk at some event, and he said he would be able to program simple feature lines to be able to do this.  The main problem they had, and probably the reason it doesn't exist, is trying to do this type of grading around corners or with varying slopes in the original feature line.  Unfortunately for now, you'll be stuck doing it slightly manually.

[sendhil.kumar]

Joel, what is the manual method you use? the circle - tangent?

[Neilw_05]

The question about how to measure slope is discussed at some length here: http://forums.autodesk.com/t5/AutoCAD-Civil-3D-General/Create-slope-perp-to-contours/m-p/1849529/hig...

[Neilw_05]

And here: http://forums.autodesk.com/t5/AutoCAD-Civil-3D-General/Grading-Contours-not-true-to-slope-values/m-p...

[sirjoelsph]

Yes the circle / tangent was probably one of the most common ones I used.  Just making sure that the circle was the same elevation as the line you were about to draw.

[ildacerveja]

Hi every one. Can you please help me making a landfill cap, step by step. I've never used autocad befor and I'm making my final school job, which consists in closing a open dump, so I need to design the dump cap, the ditch and the leachate pound but I can't found a book or video that explain it in a way that I can understand. somebody helpmeplease