Any way to add spirals automatically ?

[tonnot]

I'd want to do the next : 

Add a line, add a line, insert a curve with automatic spirals (clothoids) :

- Insert the minimal value for clotoids that comply tangency.

- If I have a standard criteria, use the appropiated values and choose the minimal value automatically.

From what I have seen, this is not possible ?

Thanks

[mathewkol]

Spirals can be added automatically using the edit curve option when creating the alignment, but I'm not sure if anything other than what you seen in there is possible.

[tonnot]

,,,, no..... 

Mathewk .... 

You have a drawing showing you an existing aligments (polylines) for I road (90 km/h)

You have the standards crtiteria select.

You want to have

- A line 

- A curve 

- A line . 

As you know, you must to insert two simetric clothoids (in the most of cases), and in the most of cases you want the right solution (provided by standarsd). 

How do you do this with C3D ? 

In addition, you want to change a simple curve by a spiral-curva-spiral. Have you to delete and reinsert it ?

Thanks. Mat

[BrianHailey]

When creating an alignment from polylines, there's no way that I know of to have it add curves and spirals. You'll need to use the "Alignment Creation Tools" to creat the alignment, just snap to the ends of the polyline. Use the option "Tangent-Tangent with curves". Before using this command, go into the curve settings and set it up to use spirals and curves.

 

[peterfunkautodesk]

Make sure that you use "Criteria-based design" and set you design speed before you start drawing. If you do this, the arcs and spiarls will be added to the alignment with the correct radius and lengths.

Regards,

Peter Funk

Autodesk, Inc.

[tonnot]

Peter....No it is not true..... 

C3D gives you the minimal value, but this is false because it does not R/3 < A < R ????????????

And of course..... there is not dynamic behaviours in this !!!! You can change the radii using the mouse but nobody change the clothoids to its right value , isn't it ?

Thanks anyway.

[peterfunkautodesk]

Your first post you asked about:

Add a line, add a line, insert a curve with automatic spirals (clothoids) :

- Insert the minimal value for clotoids that comply tangency.

- If I have a standard criteria, use the appropiated values and choose the minimal value automatically.

And this is possible with Civil 3D by using a design criteria when you design the alignment.

For the additional requests for the calculation of the length of the spiral, I'm not sure what design standard you are using, but we have 30+ country kits with different design standards in them. You should make sure you are using the correct one. If we don't have one for your region, the design standards can be modified.

As far a changing the spiral lenghts, no we don't change the spiral if you grip the curve, but a design check can flag the spiral as being incorrect if the arc is grip stretched. By design, we don't want to automatically adjust spiral length when a curve radius is changed, and leave that to the engineer to do if they fall outside of the design standards. 

Regards,

Peter Funk

Autodesk, Inc.

[tonnot]

Peter, I dont agree with you. 

You are obliged to fgollow the rules .... 

If you change the curve, the clothoids have to change automatically

Thanks