New to civil 3D modeling..Help with channel design

[sonnyamorales]

Ok, so I am new to desiging with civil 3d and have been reading and searching froums to help answer some questions, but i am still finding it hard to understand and know if i am doing it right.

So here is were i am at.

I have:

EG surface

EG profile

Proposed alignment

Proposed channel profile

I am having trouble using/understanding the channel subassembly.

1.  If i have already set my bottom elevation of channel, what do i put in for the "depth" parameter within the assembly? does not allow "0"

2.  need my side slopes to be 3:1 until the hit the EG.  what controls all this?  the side slope parameter creats the slope, but than it just runs up to the "attachment point" im assuming....do i need anything in the other parameters or do i just set their targets to my EG surface and it will daylight to it?

3.  along the same lines of the above question, what if i need my side slopes to be 3:1 for 5' than 2:1 till EG? 

4.  Do i need a daylighting subassembly to accomplish what i want?

If this does not make sense, please let me know and i will do my best to explain my confusion.  I have posted on other forums with some help, but am still onfused so thought id try a different one.

[sonnyamorales]

Ok...I think i am finally getting somewhere with this thing...thanks alot!!!

Quick question.

Is calculating the cut/fill as easy as selecting a surface and hitting the volumes tab, than creating a volum entry and using the EG as my base surface and Proposed channel as my comparison surface??

[sboon]

Yes but....

Looking at your earlier screenshot you have a corridor surface with no boundary, so the program is triangulating across areas where you probably did not intend to have a design surface.

If you open the Boundaries tab of the corridor properties dialog then you should be able to right-click on the surface name and work from there.  Assuming that you have daylight feature lines then you can use them in the boundary definition.  Otherwise you might have to use the corridor extents option.

[sonnyamorales]

Ah I see.. So though it may look correct it is not.. I don't remember adding a boundary, so will look at that first thing in the morning...not sure if I have daylight feature lines or not..will let you know how I make out. Thanks

[toyhonda86]

Looking at your previous screenshot of the subassembly properties I only see the P2 code under your point codes.  This is the generic code for points.  You can however select the links and add codes to the points just as you defined them for the links.  This will allow you to customize the links even further and generate feature lines based on those point codes.  I usually add the code "Daylight" to the outer links that attach to my EG surface.  Then when creating a boundary  in the corridor properties you should be able to select corridor extents or add interactively and select your daylight feature lines.

Below is one of my generic Link Slope to Surface links.  Notice under point code it says "Ditch_Out".  You need to make sure when adding these codes that they are case sensitive.

[fcernst]

No, do not do earthwork calcs comparing Top surface to EG for channels.

This channel will have some sort of lining such as grass with a topsoil layer, riprap or concrete. Get the required channel section from your engineer.

Use subassemblies that have material capabilities such as the Lane subassemblies and Daylight subassemblies. Then do earthwork calcs between the Datum surface and EG.

[sonnyamorales]

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@toyhonda86 wrote:

Looking at your previous screenshot of the subassembly properties I only see the P2 code under your point codes.  This is the generic code for points.  You can however select the links and add codes to the points just as you defined them for the links.  This will allow you to customize the links even further and generate feature lines based on those point codes.  I usually add the code "Daylight" to the outer links that attach to my EG surface.  Then when creating a boundary  in the corridor properties you should be able to select corridor extents or add interactively and select your daylight feature lines.

Below is one of my generic Link Slope to Surface links.  Notice under point code it says "Ditch_Out".  You need to make sure when adding these codes that they are case sensitive.

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So I should add a "daylight" point code to the links that hit my EG?  in order to make the surface triangulate properly?? 

[sonnyamorales]

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@fcernst wrote:

No, do not do earthwork calcs comparing Top surface to EG for channels.

This channel will have some sort of lining such as grass with a topsoil layer, riprap or concrete. Get the required channel section from your engineer.

Use subassemblies that have material capabilities such as the Lane subassemblies and Daylight subassemblies. Then do earthwork calcs between the Datum surface and EG.

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Hmmm so i can use the lane subassemblies in the same way that i used the links ones...to create my channel..is that what you are saying?

Now that I think of it that would make more sense, as we will be adding a layer of material to the bottom.  Ill see what i can work with to make the most sense.

Thats what i love about CAD and the community, so may ways to do one thing!!  thanks, will update as i go.

I think i might keep what i have already and do a second one using this idea.. 🙂

[sboon]

Point codes are used by the corridor to draw the feature lines along the length of your design.  They're useful for organizing the display of things - have one code for ditch bottom and another one for the daylight, then use different styles to display those feature lines.  The points are not individually used for surface creation, but you do have the option of using the feature lines or the corridor links or both.  Typically I just use the links, and then apply the Daylight feature lines as the surface boundary.

[fcernst]

"Thats what i love about CAD and the community, so may ways to do one thing!!  thanks, will update as i go."

It's much more than that. This is the correct way.

• Your engineer has done hydraulic capacity calcs to determine a required channel section that your Assembly needs to reflect as the Top surface.
• Your engineer has done shear stress calcs to determine a channel lining system (i.e. materials) consisting of layers of materials that have specific thicknesses.

You need to provide accurate earthwork numbers to balance the site. That is the comparison between Datum and EG.

You will need to get a sketch of the required complete channel section from your engineer, then build your channel assembly appropriately with the specific layers of materials.

Hope this helps.

[sonnyamorales]

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@fcernst wrote:

"Thats what i love about CAD and the community, so may ways to do one thing!!  thanks, will update as i go."

It's much more than that. This is the correct way.

• Your engineer has done hydraulic capacity calcs to determine a required channel section that your Assembly needs to reflect as the Top surface.
• Your engineer has done shear stress calcs to determine a channel lining system (i.e. materials) consisting of layers of materials that have specific thicknesses.

You need to provide accurate earthwork numbers to balance the site. That is the comparison between Datum and EG.

You will need to get a sketch of the required complete channel section from your engineer, then build your channel assembly appropriately with the specific layers of materials.

Hope this helps.

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Ahhh yes, turns out my channel is more complicated than i expected.  good news, is i got good practice as far as naming and labeling everything, and how civil 3d works 🙂  bad news, i need to do it again hahah

so this is what my typical section would look like (i just drew this up quickly)  seeing this, what would be the best assemblies to us to get my desired result?  I am looking at different subassemblies in the help file to see which might work, but figured i put it on here as well, as you guys have been a tremendous help so far.  

Example: the channel one i previously tried does have show a lining depth, but can you add multiple linings? or is that a seperate assembly you have to add?

Some notes:

My profile runs along the bottom of my channel, problem i ran into with the depth parameter (though can fix that with a .0001 as previsoulsy mentioned)

If i do that, how do I control how far my side slopes run? in some areas I will have just a 3:1 to EG but in others it will be 3:1 for about 5' than 2:1 to EG.

thanks

[sboon]

Two ways to approach the channel bottom and lining materials:

• You could use one of the lane subassemblies, like LaneSuperelevationAOR and re-purpose the default codes to what you need.  Pave1 = 10" fill, Pave2 = 6" fill, etc.  You'll need two copies for each side, with the outside one sloped to 33%
• There is also a GenericPavementStructure sub which you can stack up to form your material layers.  This would allow you to customize all of the codes but it's going to require more work to set up the assembly properly, so that all of the layer widths match etc.

For the daylighting I would probably use DaylightGeneral.  It will allow you to set up the grade breaks in the section automatically.

[sonnyamorales]

Alright, I think i got the channel subassembly down (using the lanesuper you suggested.  Now the daylighting is confusing me as there are so many options.

The image shows the assembly i currently have, In the daylight subassembly, the only thing i changed was

Cut test point likne - 1

Cut 1 slope - 3:1

but not seeing it change anything??  Do i need to have a width for the cut link?

For this particaular section i just need it to have a 3":1 slope till it hits EG.

[sboon]

Your best bet at this point is to read the help file tor the subassembly and figure out how you want it to work.  Start at the Behaviour section first, then you can go back and decide which parameters you need to change.

[sonnyamorales]

I have been, its just confusing to me.  I will continue to work at it or maybe use the linktosurface for this portion.

thanks for the help and patience 🙂

that goes for everyone who helped me out

[sboon]

Here's a set of parameters which should work for you.  With these settings the sub will not attempt to build any ditch.  It will start by testing for cut or fill.  If it is in cut then it will apply the Flat Cut slope up to the height limit.  In this case I've set that limit very high, so the assembly should use this slope all of the time.  If the assembly is in fill then it will apply the Flat Fill slope in the same way.

If the Flat slopes don't work, either because the sub hits the height limit or it runs off the edge of the surface then it will switch to the Medium slopes.  If one of those doesn't work then it will try again with the steep slopes. 

[fcernst]

For this particaular section i just need it to have a 3":1 slope till it hits EG.

Use the DaylightMultiIntercept subassembly. Don't use the Generic Links because your earthwork will not be correct.