Most Efficient CAD Method For Grading A Site 3

[JSiteDznr]

Hello!

I am an engineer looking to be more efficient at grading. I mostly work on commercial sites and find that once grading is complete, someone in my office makes a change and the entire parking lot needs to be re-graded. No issues with that, it is apart of design. My question is, is there a function or method in CAD/Carson Civil Suite that will allow me to grade the lot, but edit certain spot grades quickly and have the contour lines adjust automatically? I am currently doing all the grading by hand.

Thank you so much!

 

[TerryScan]

I use 3Dpolylines and a multitude of Carlson tools (under 3D Data menu) to edit them to do grading. When making revisions, I typically edit the 3D linework and re-solve the TIN surface.

However, one can also use the "Triangulation Surface Manager" to edit spots (among other things) in the surface and see the contours update dynamically.

 

[Twinkie]

Call me old fashioned, but there is just no substitute to putting a scale on your plans and grading that out by hand with your calculator and pencil.

 

[GeoEnvGuy]

To make a grading for parking lots
3d polyline your outline boundary and islands
3d polyline your square catch basins/light posts

Make surface

3d view surface
Add line not polyline to make breaklines where you want
Use grading tool to join to existing surface at what perimeter slopes you want
Check cut fill
Raise lower graded surface to balance
Don't forget to strip off grass about 10 cm

The first stage of site investigation is desktop and it informs the engineer of the anticipated subsurface conditions. By precluding the site investigation the design engineer cannot accept any responsibility for providing a safe and economical design.

 

[GeoEnvGuy]

Other tips using CIVIL
if you want contours you can draw them in as polylines and use the offset command then remember to change the elevation of it.

If you know where your boundary is and want to work off that
Draw polyline on boundary
convert to feature line and clamp to existing topography surface
grading tool new feature line to elevation at preferred slopes
and that will get you a level starting line (usually with some errors)
Redraw line by eye as polyline at elevation slightly inside or on obvious change in directions
this will get you a flat starting surface

The first stage of site investigation is desktop and it informs the engineer of the anticipated subsurface conditions. By precluding the site investigation the design engineer cannot accept any responsibility for providing a safe and economical design.

 

[JSiteDznr]

Wow thanks everyone! Super helpful!

 

[TerryScan]

Twinkie: You are old fashioned.

 

[chicopee]

TerryScan, Twinkie may be old fashion but remember some of the greatest civil engineering work such as dam construction were done by old fashion method and old fashion method were incorporated in many engineering disciplines.

 

[Ryan J. McGowan]

Regardless of the software you use, The first thing you can do is analyze the site for critical and non-critical slopes. This cuts down the workload by filtering your mind down to what has to change. If your site is designed to keep critical areas detached from one another as much as possible, then sometimes making a change can be as easy as raising and lowering a subarea and recalculating only the slopes between them. Keep your design as component subareas as much as possible.

 

[JSiteDznr]

Got it Ryan, thank you, what do you do around the radius of a curb? I find that the 3d polylines work well, however, say I want to raise the ground between the two end points of a curb radius. I would need to enter a new elevation for each of the points interpolated along the radius. The problem is, theres a million points lol. Do I just redraw the radius? Use a series of straight lines instead?

Thanks!

 

[eea]

I typically don't draw the radii in 3D and simply grade a straight 3D line between the two radius end points for a quick and dirty TIN. Maybe at the end I would, but the reality is that the touchdowns are the critical ones. Are you doing a 3D offset to model face of curb and the curb pan? Keep it simple, rough grade until you are locked in to a final design. You NEVER know when the Architect will come back with a change that'll throw everything you've done nearly out the door.

 

[Ryan J. McGowan]

I'm using Civil 3D and use feature lines, which will grade it as a constant slope along the circumference of the curve, and you can move the entire feature line up and down, or vertex-by-vertex, change the radius, etc. However, if all I want is a TIN for volume calculations, I'll consider just roughing in with scattered breaklines and I'm not worried about radii under 10 feet or so. Maybe I'll overshoot the BCR and ECR for a better volume fit. If you're creating a TIN to generate contour lines for you, an arc that is stretch in the Z direction is not an arc. It's a helix. In AutoCAD, there is a Helix command. Not sure about Carlson. If not, maybe you can find a plug-in that creates a Helix. Personally, I limit TINs to just volumes whenever possible, and draw contours manually. No cleaning up messy TINs, worrying about curves, or having to offset paving depths. Unless the project is going to have dozens of contours or more. Then I'll consider fully modeling the TIN.