grading an intersection 1

[daddyman]

Hi, I am designing a subdivision using civil 3d.
I have created corridors and surfaces.
The intersections are 3 leg T'S.
Can anyone tell me how to fix the intersection grading?

 

[francesca]

I found that it was easiest to do the intersections by hand with liberal use of spot shots. Yes, we could use the (Terramodel) functions to do it for us, but that was almost as time-consuming to set up, and we mostly used them for cul-de-sacs. Of course, our contractors used to smooth out any high or low spots if we were sloppy with our grades anyway. For the most part they'd all been building roads for three times longer than I'd been a civil engineer...

 

[daddyman]

Thanks Francesca,
Civil 3d grades roads but the intersections are all wrong.
The last job I did, the contractor used computer/gps controls on the equipment and fed our drawing information into it. The road was fine but the intersection had a 4' deep whole in the middle of it. I am not an engineer, I am a civil designer (new) learning as I go. Our civil engineer quit and left me playing in the dirt so to speak.

 

[runoff]

I agree with francesca, daddyman. Peak the intersection with a spot elevation. The idea is to insure you keep the flow of water going in four sides of the pyramid you create. Maintain atleast 2% to the gutter and let gravity do the rest. Check out the federal highway administrations web site and their design criteria. They have a lot of good information pertaining to highway and other roadway design methods.