Alignment can't be Done in Civil 3D

[onsionsi1]

Hello everybody,

I can’t believe that Civil 3D can’t draw my Horizontal Alignment shown in attached file.

I figure out many tricks to solve any issues in Horizontal Alignment except my issue.

And let me tell you that MX Road can handle my issue very easy so hopefully Autodesk can solve like my issue easy in next releases.

I will explain what I have in my attached file.

First, I want to draw fixed arc R=500m & 1000m and I want to attaché between these two curves with  R=90m with  single curve and have spiral in A=80 and spiral out A=80

So, hopefully can someone have a trick and advice to solve my issue.

Thank you in advance.

[onsionsi1]

My first attachment in feet so i'm sorry for that error and you can find my new attachment in meters.

Thank you in advance.

[HansSMS]

The large arc and the polyline on the southern side overlap. I've just moved the endpoint of one arc to get it to work. See attached drawing.

[onsionsi1]

Thank you Mr.Hans for your effort.

But actually my issue is how to attach a spiral in and out with A=80 because the location of Circular Radius=90m is depend of a spiral value.

Thank you in advance.

[sboon]

There is probably a better solution but what I did was to place a fixed curve using the center point and radius method, then attach the reverse spiral-spirals between the curves.  Once that was done I opened up the Alignment Grid view panorama and started moving the center point of the 90m curve.  It took a few minutes to work out which direction I needed to shift but it's one option at least.

Steve
Please use the Accept as Solution or Kudo buttons when appropriate

[onsionsi1]

Thank you Mr.Steve for your effort and i'm really appreciate for that.

But actually i didn't figure out how do you do that because when i followed your instrucations the command box gave me the following message

Cannot add a free spiral to intersecting arcs.
Current spiral definition: Clothoid

So i will be apprecaite for your advice.

Thank you.

[onsionsi1]

Alsp Mr.Steve which version you are using civil 3d.

[sboon]

This is exactly the same problem that Hans commented on earlier.  It is not geometrically possible to have spirals between tangent or intersecting reverse curves.

If you look at the attached picture you will see two alignments which have identical curves.  One of them has a tangent line attached (in yellow) while the other has the same tangent line but with a spiral (in red).  The spiral forces an offset in the line.  If you wanted to join the cyan line to another curve with a spiral then that curve would have to be offset also.

Steve
Civil 3D 2012 & 2013
Toshiba Qosmio X505-Q890
2 x i7 - Q740 quad core CPU's
8GB of RAM
60GB SSD + 500GB HDD
NVidia GeForce GTS 360M - driver 8.17.13.0697
Win 7 Home Premium
Please use the Accept as Solution or Kudo buttons when appropriate

[peterfunkautodesk]

The key is that the 90m arc needs to have the center point shifted by about 3 or 4 meters for the spirals to work. With the current geometry where all the curves are tangent there is not solution.

Regards,

Peter Funk

Autodesk, Inc.

[onsionsi1]

Thank you Mr.Steve and Mr.Peter for your advice and support.

I need some clarification of some thing i don't know why it's coming wrong with me.

Let me explain what happened with me.

When i press Floating Reverse Curve with Spirals (From curve, two points) and it asked me which i want A value or L length i selected A value but the values came as length not A value.

Is this a bug or what????

Despite if i press Floating Reverse Curve with Spirals (From curve, radius, through point) it came true if i selected A value and it is working right.

Your advice will be appreciated.

Thank you in Advance

[onsionsi1]

Mr. Peter and Mr,Steve

Let me tell you about using a Floating Reverse Curve with Spirals (From curve, two points) it will solved my problem inshaa allah if it's coming as i want by A value not a L length only and i will let you know how to draw my issue.

So let me know is it a bug or i'm fault.

Thank you in advance.

[sboon]

It appears to be a bug.  I tried the command also, making sure to switch from the default Length input to A value.  The Panorama display shows the resulting spiral data.

I assumed that I would be able to fix this by changing the A values after creating the spirals, but the software only accepts input for the two lengths and the first A value.  Any changes to the second A value creates a "Could not Solve" error.  I was able to find a workaround where I set the first A value then adjusted the second length by trial and error until the second A value matched.

Steve
Please use the Accept as Solution or Kudo buttons when appropriate

[onsionsi1]

Thank you Mr.Steve for your effort and i'm highly appreciated for your effort and advice.

So how Autodesk know that there is a bug like our issue because i would like to send my bug issue to them or if you can do that because you are expert in Autodesk and i think it is the best way and they will listen to your advice also.

Thank you very much Mr.Steve.