AUTOCAD CIVIL 3D TIP: HOW TO CREATE RETAINING WALLS

 Smart Retaining Walls

I've seen a couple of different ways people use to create retaining walls in Civil 3D.  More times than others, I see people creating a grading group representing their retaining wall, generating a surface with it, and pasting it into their site surface.  It generates contours which is the desired result.  This is a fairly quick and simple method.

RetainingWall

I prefer to create a more BIM-like retaining wall with a retaining wall assembly.  My reasons for using this method are:

  • Retaining wall assemblies recognize when they are in cut or fill and will shift codes around accordingly.
  • Retaining wall subassemblies have adjustable parameters.
  • Retaining wall code sets can be applied which not only affect the display of the wall in plan and model, but apply elevation labels automatically in section.
  • The top of the retaining wall can be controlled with a profile which makes it very easy to visualize and design the top of the wall in comparison with a surface.  Also, when the proposed surface, top of wall profile, or retaining wall parameters change, the retaining wall and composite surface update.

Here are the steps:

  1. Grade your proposed site out to the location of your wall to generate a proposed surface.
  2. Create two alignments:  one along where the proposed grade (P) will intersect the wall and the other along where the existing grade (E) will intersect the wall.Alignment
  3. Create surface profiles and the profile view for the alignment representing the high side of the wall:  Alignment P will use the proposed surface and Alignment E will use the existing surface.RetainingWall2
  4. You may superimpose the other alignment's profile into the profile view for visualization purposes.  You may also temporarilly remove the vertical scale exageration from the profile.RetainingWall3
  5. Layout the smooth grade for the top of the wall.  This will be the "hook in" point on the subassembly which is where the high surface ties in.  The distance between the "hook in" point and actual top of wall is adjustable in the subassembly parameters.RetainingWall4
  6. Create a corridor using an assembly created with an appropriate retaining wall subassembly.  The baseline will be based on Alignment P.  You will configure the existing surface and the Top of Wall profile in as targets.RetainingWall7
  7. Create a corridor surface using the RW_Hinge and RW_Front feature lines in the corridor.  RW_Hinge will always be where existing grade intersects the wall.  RW_Front will always be where proposed grade intersects the wall regardless of whether the wall is in cut or fill.  The point codes swap places depending on what the condition is.RetainingWall5
  8. Finish by creating a composite surface.  Paste the existing, proposed, and retaining wall surfaces into the composite surface in that order.   Finish off the grading around the retaining wall area as necessary.RetainingWall6

The contours in the wall can be masked with a hide boundary.  Also, you can attach a daylight subassembly to the "hook-in" point to control grading from the retaining wall to the existing surface which is what I did in the above illustration.

Location: Pune, Maharashtra, India

Comments

Post a Comment

Popular posts from this blog

AUTOCAD CIVIL 3D - GRADING

Image
Heads Up Grading for Parking Lots In the good ol' days, before data collectors were in wide spread use, we used to get our existing topo on paper. We'd have to throw it over a big ol' digitizing board and trace it with a puck. This was referred to as digitizing which was a very time consuming task. Later, we were able to have the paper scanned, insert the image into AutoCAD, scale it up, and trace it on screen. This was referred to as "heads up digitizing" which was a lot more efficient and faster. I've coined this term "heads up grading" for those who give up the paper, scale, and calculator way of grading to use the grading tools in Civil 3D instead. The example presented in this post will show how quickly and efficiently one can arrive at a grading solution using this method.  If there are any fundamental concepts in this post that you do not understand, please refer to  Mastering Civil 3D by Richard Graham & Louisa Holland . The illustration
Read more

AUTOCAD CIVIL 3D TIP: HOW TO ADD NEW PIPES TO PRESSURE PIPE CATALOGS

Image
  Pressure Pipe Networks are fairly new to Civil 3D, and anyone who has worked with them has noticed that Civil 3D only comes loaded with ductile iron piping as an option in the parts catalog. Whether Autodesk adds more piping materials to the standard catalogs in future releases remains to be seen, but most users would like to see a PVC parts list at the very least at some point. As for now, there are options to buy pre-made parts lists from private companies, but they can cost thousands of dollars. A more affordable option to those who really only use a handful of pressure pipe sizes/materials is to build your own, and import them into Civil 3D. No special software is needed, and a basic pipe size can be created and imported in a matter of minutes. Creating fittings and appurtenances is a bit more involved, but that will be covered in the next tip. Here are the steps for importing new pipe materials and sizes: 1) New Catalogs and pipes can be added very quickly through the Content Ca
Read more