Surface Subgrade Creator Part I

Occasionally I build surfaces for projects. To get somewhat accurate earthwork numbers you have to account for the material that makes up the sidewalk, pavement and topsoil (ie. the material that usually comes from offsite). To do this I usually create a subgrade surface or datum surface. This is usually labor intensive and I’ve been thinking about automating it. This will be the first in a series of posts of creating a program that does goes through my thought process and steps in creating it.

The first thing I have to decide is how to accomplish it. I’ve thought of various ways to accomplish the task, but have decided to go the easy route. I’m thinking the program will do the following steps:

1. Have the user select the finish grade surface, “FGSurface”.
2. Have the user select a collection of closed polylines that represent a single type of subgrade.
3. Prompt the user for the name of the subgrade, “Type”.
4. Prompt the user for the depth of the subgrade.
5. Create a surface with the original surface name hyphenated with the subgrade name, “FGSurface-Type”.
6. Paste the “FGSurface” into the “FGSurface-Type” surface.
7. Move the “FGSurface-Type” surface down the the required amount.
8. Add the first polyline as an outer boundary.
9. Add the remaining polylines as show boundaries.
10. Prompt the user to select the subgrade surface to paste the “FGSurface-Type” into or let the user create it.
11. If the user opts to create it a surface named “FGSurface-Subgrade” will be created and the “FGSurface” will be pasted into it.
12. End the command.

This is going to be version 0.1. Possibly in version 1.0 I’ll add a dialog box so the user can fill in a the information for multiple subgrade surfaces. As time is available I’ll do a post on each of the 11 steps and hopefully in the end I’ll have a working program.