How to add breakline to surface and project slope from that breakline

[Anonymous]

Hello learned scholars and helpful people;

I am doing a gravel pit reclamation where they want me to contour the reclaimed site. I have a slope of 20:1 from a specific offset on the west side, and 3:1 slopes from specific offsets on the other three sides.

I have an original ground surface built from survey data, and then another surface called overburden which was modeled using the outer points of the original ground surface and elevations provided by about 8 or 9 test holes (Sketchy but it's all I have.) I want to project the outer slopes down to the overburden surface and then contour that to show them what the area will look like after reclamation. I also have data for the gravel depth (below the overburden) which would be cool to model because then I could get volumes but for now I would be ecstatic to be able to do my slopes.

From the twelve thousand videos I have watched, it seems that I need to make breaklines out of my tops of slopes (feature lines) in order to assimilate them into the model, otherwise they are at 0 elevation and I can't project slopes. (I even tried drawing a 3D polyline from each end of the model but of course that isn't accurate. I have made a breakline from my feature line on the west side, and it gets absorbed by the model and looks nice, but now I can't figure out how to project from THAT line down to the overburden surface as there is no longer a feature line to project from. 

I hope all of this makes sense. Any help, videos, anything would be very much appreciated.

Thank you

Liesl

[Joe-Bouza]

When you say reclaimed overburden you want to grade the pit, right?

All great ideas suggested here .  your permit lines will want to be filleted. I have no sense of scale but would guess 25-feet. I have no faith in gradings with multiple criteria and transitions but you can try the methods suggested. 

you will use a grade to surface criteria lets say starting on the west side and working clockwise

limit the projection to the straight portion at 20:1 , move to the north and repeat with 3:1....continue around the site.

add transitions in the corners ... that is a command on the tool bar. Now if we avoided crazy collisions with the 20:1 slope infill the bottom.

If the grading blows up consider going back to my original post.

Can you share your file

[Joe-Bouza]

@Anonymous  forget what I said. that aint going to work. I tried with some dummy data and the gradings just go kblooie on me. better go with the other suggestions

[Apex-Solutions]

Hello @Anonymous 

Apologies for assuming you understand all the basic's.  Teaching the basics and suggesting workflows are two very different things and based on that I would suggest that you attend a Essentials/Fundamentals course for Civil 3D in order to better take advantage of the Autodesk Civil 3D forums.

However here are the missing parts from our suggestions:

• Assigning surface elevations to feature lines .
• The basics of grading
• Understanding how sites work in Civil 3D.
• Combining surfaces
• Creating a transition grading.

Some of these videos are old but they do hold a wealth of information. 

I hope it helps.

[Anonymous]

Thank you Marnus and no apologies necessary - I should have been clearer. We work in environmental consulting so mostly utilize the GIS functions of Civil 3D, and even though have been using AutoCAD for almost 30 years it is so multi-faceted and industry-specific that it's impossible to know everything. I used Eagle Point many years ago for earthworks when we were designing ponds and landfills at an engineering firm but things have definitely changed over the years and like a language, if you don't use it often you quickly forget.

I appreciate your suggestions and for breaking down the specific training modules. 

Best,

Liesl

[Anonymous]

Hi Marnus,

I have been able to create the reclaimed surface that slopes down from original ground to reclaimed overburden. (I ended up just creating a new surface using the elevations of sand/gravel from the testholes. 

How do create contours of the base of the pit? I used infill but I expect to see contours. The client is complaining about this and wants to see the base contours.

I am attaching the dwg file. 

Thank you

[ChrisRS]

Since you posted a file, I took a look at  it.

Your grading objects look fine but you need to get them into a surface.

I ran purge and audit on the drawing, but the gradings disappeared.

I cleaned up the a little and saved as LAST ONE_audit

1. You only need one feature line. I joint the two FLs and filleted at the NW and SW corners.
2. Create a site "Reclaimed"
3. Add a grading group "Reclaimed" to the Reclaimed site. Set automatic surface generation for "ReclaimedSlopes"
4. Move the closed FL to the Reclaimed site
5. Create the 20:1 and 3:1 grading objects in the Reclaimed grading group. Target: Extracted Overburden (1)(1)
   1. You will need to fuss around at the NE and SW corners. The RelaimedSlopes surface will be automatically created. 
   2. Use the object viewer to look at the surface. There are expected gaps at the NW and SW corners and a surprise gap at the SE corner. 
   3. Use creategradinginfill to fill the 3 gaps.
6.  Create surface "RecoverFloor"
   1. RecoverFLoor, definition, edit paste surface Extracted Overburden (1)(1)
   2. Select the RecoverSloped surface; ribbon: Extract from Surface, Extract objects: Border.
      This will create 3d polylines at the inner and outer boundary of teh sloping sides.
   3. Add the polyline that defines the floor to the RecoverFloor definition as an outer boundary. This trims the surface.
7. Create surface "Recover"
   1. Recover, definition, edit paste surface RecoverSloped
   2. Recover, definition, edit paste surface RecoverFloor
8. Done

"RecoverSLopes" surface. Note areas to be corrected.

"RecoverFloor"

"Recover". Note wavy slope.

I believe that this is the surface you wanted. Contours are shown below, and the file is attached. 

If you look at this carefully, you will find that is difficult to construct.

1. The pit floor is not flat or uniformly sloped. I follows the top of the sand and gravel strata. If I understand this project properly, you will be mining the sand and gravel then using excavated overburden material to fill the pit back up to the top of the sand and gravel strata. I do not see the value to recreating this irregular surface., rather than a flat or uniformly sloped surface.
2. The top of pit feature line is straight, but the elevation follows the irregular surface. When projected downward, rather than a flat surface at 20:1, you are designing a wavy surface that is difficult for the surveyor to layout and for the equipment to grade.

An alternate approach is to establish a Feature line at the bottom of the pit and grade up from there. This will give flat slopes and an irregular daylight line at the top of the pit. The power of Civil 3D is that you can control the top daylight line by dragging a point of the bottom FL. 

Good luck!

[Anonymous]

Chris! Thank you SO MUCH! I have lots to learn but I was able to create for the client what he wanted. Here is the fruit of our labours: 

I feel like I owe you a great big bottle of wine - you and all other fantastic people on here who helped!

Liesl

[ChrisRS]

Your exhibit looks good!

Glad to be of help.

Civil 3D documentation is pretty good for the "How To" straightforward workflows, but not so good on "Why" and complex workflows.

Recognizing that the Reclaimed surface requires the ReclaimedSlopes surface and ReclaimedFloor surface is not something you will find in the documentation.

Recognizing that ReclaimedFloor surface matches the Extracted Overburden surface and that the boudary needs to be "borrowed" from the ReclaimedSlopes surface is not in the documentation.

After discovering these kinds of relationships a few times, it almost becomes second nature.

Good luck!

[Joe-Bouza]

Very nice.

I like to transition the 20:1 and 3:1 . The other day I couldn't get a grading to work on imaginary data using the cross section information.

the real data all worked great. I used the bottom daylight to clip the overburden surface for the irregular bottom