This past year or two I had really wanted to begin implementing Civil 3D in our projects. I had planned to use a subdivision as the “pilot project”, but the engineer on that project shot me down. He was an old timer and wanted to do things the old timer way, his way. I did end up using that project data to practice with, but that’s all I got out of it.
Later that engineer left the company and I had another one to work with. We had a project where a new subdivision was having issues with some flooding. Another engineer (from a different company) had apparently graded it too low or had some miscalculations in his drainage system. Perhaps the contractor goofed. Who knows. Either way we were stuck with fixing the error.
We went through several alternate designs, one of them being a ditch that crawled along the back of the subdivision which backed up to wetlands. Our discharge point was a ditch behind the wetlands so we had to get our drainage from one side of the wetlands to the other. Previous attempts to design a ditch and/or pipe system through the wetlands were immediately flagged so we needed a different option.
I think we ended up piping the water along the path that our ditch took in the final design, but I kept the file with the ditch for my own file. Well, I had kept it. I had saved it on my local computer which was stolen during a break-in one evening after hours. Fortunately I had saved a file on the network which at least had my surfaces and x-sections. At any rate here’s what the plan looked like:
(click for larger view)
As you can see in the typical sections it was modeled as a standard ditch and had a berm added where necessary to keep it from polluting the wetlands. In this case, since I am still mostly a Civil 3D layman, I used generic links for building my assembly for the corridor. There may have been a better way to do it, but I went with what I knew at the time and it worked just splendidly.
My alignment was the centerline of the ditch bottom. It grades at 3:1 (if I remember right) in both directions. On the sub-d side it grades to either the back of lots or to the pond bank and then the other side grades into the wetlands. There were some low lying areas on the wetland side, thus the berm.
After modeling the ditch I created x-sections and then extracted my cut-fill quantities and created a report for the engineer to analyze and use in his documentation.
If you are a Civil 3D hopeful who needs help with the program let me know and I’ll do what I can. Like I said, I’m still a bit of a layman, but I’m more than willing to help a fellow cadd’r when I can. I’ll give you one hint to help you get started which can help more than most drafters/designers know or will admit… F1
