AutoCAD Civil 3D

[#1]

C3D Gurus,

It's Friday, which is a great day to solve a fairly complex Alignment layout for the sake of bragging rights to your peers!

I have an old alignment that I know works on paper and solves to within a second that I need to recreate in Civil 3D, however, it has a couple of spirals in it that are bracketed by curves and it is proving a challenge to recreate in Civil 3D.  I struggle with Alignemnt layout generally, and spirals just make it worse.

I thought I would post it here to see if anyone can crack this nut and post the commands\workflow used to solve it here.

Below is a Dropbox link to a PDF that has the geometry notes needed for layout.  Curves are highlighted blue, spirals green.  

http://dl.dropbox.com/u/4776527/Alignment.pdf

I'll be watching email as I work on it independently so just reply to this thread if you have questions\comments or the solution!

Thanks in advance and good luck!

[#2]

I'm no guru by any definition of the term, but I think the solution is pretty simple.

Layout the incoming and outgoing tangents. Then use the Free Compound Spiral-Curve-Spiral-Curve-Spiral (Between two tangents) tool as shown in the screen capture. Since you don't have an incoming spiral just set the length to zero for the first spiral when prompted.

[#3]

That worked, only, it is making the delta larger in the first curve by a few seconds which lengthens the entire alignment by about 0.06'...  This isn't a huge deal, but we get it to close on paper to within .01 using the same input criteria....

Thanks for the tip!