The other day I talked about how we used a flat subassembly and some rock data to create surfaces that approximate different rock layers. Today, I will show you how we used that information to come up with some quantities of the different types of material that needed to be removed.
The goal of the project was to minimize the amount of blasting that needed to be done in order to install public sewers for an existing town. We had to find the optimal layout, and explore the possibility of using lift stations and forcemains if necessary.
There are a few ways you could do this. First, we tried using pipe networks and pipe rules to lay out the system, but we found it to be too much detail at this stage of the game. Pipe networks are wonderful things, but they aren't designed for being super flexible during early conceptual design. So after a few tries, we settled on a workflow where we made alignment styles that looked like pipes. A few weeks ago I wrote about using alignments and profiles to make pressure and conceptual pipe networks. This is the project where I began using this technique.
Since the rock corridors we made didn't necessary follow the same paths as our sewer layouts (and those 1:1 profiles were a bit hard to read), we sampled the rock surfaces on to our pipe profile views. This helped us stay out of the toughest areas.
Once we had the alignments and profiles made, we created a corridor using the pipe trench subassembly.
This was back in Civil 3D 2007, so there were only two options, and both of them needed to be hooked onto a profile. (This also contributed to why we used the profile technique instead of pipe networks- to reduce redundancy).
(If you'd like to see more examples of pipe depth screen shots, my original flickr set that I created when proposing this project is still around. Holy wow- September 2006. That was a CRAZY month.)
From these corridors, we could build a pipe trench surface, then compare the trench surface against the different depths of rock. I'll spell out that process in a day or two.
Civil 3D 2009 subscription customers can download pipe trench corridors that actually latch onto the pipes themselves.
If you'd like to download them, go to the Subscription Center and log in. If you are not sure if you are on subscription, or you don't know your login information, check with your CAD manager, or call your reseller.