Modeling Corridor Subassembly Transitions - Retaining Wall End

[ndegan]

When modeling corridors I have always had an issue with how to model a transition in a retaining wall.

The attached image shows a trail corridor. 

• The trail and shoulders are 1 assembly using a centerline alignment as the main baseline.
• The connections to EG (both left and right) are using corridor feature lines as baselines in order to set regions independent of the centerline assembly. This gives more flexibility for placing retaining walls.
  • The shown connections are a link slope to surface at 3:1 and a retaining wall. There is no gap in the regions from 3:1 to retaining wall.
• The entire corridor is 5' of fill above EG. 

I want the retaining wall height to taper from the connection to EG, upward to meet the point where the 3:1 assembly and the wall intersect, at a 3:1 slope. This is a very common occurrence in these types of projects. In the past I have tried a couple things. I've ignored the surface and just drawn polyline contours. I've made a gap in the 3:1 and retaining wall regions, then manually created a transition using feature lines and adding them to the corridor surface. Both of these options require a lot of work and are not dynamic with the corridor. I'm looking for a better way.

I have seen videos from Jeff Bartels showing ways of creating transitions in corridors (links below) but I don't know if I can make these options work for a retaining wall transition of this nature. If someone knows how to make these work in this application, this would be ideal because they would be dynamic with the corridor.

Jeff Bartels Applying Transitions to Virtually Any Civil 3D Subassembly - https://www.youtube.com/watch?v=W-f4Ep7TXyE

Jeff Bartels Modeling a Civil 3D Corridor with Variable Slope Daylight - https://www.youtube.com/watch?v=NKyTjaUL3J0

So my question to everyone is, How do YOU model retaining wall transitions?

[ndegan]

Fred,

Exactly! I have been messing around in SAC trying to take the concept that Jeff Bartels shows in one of his videos and apply it to my retaining wall heights. For a varying height of my retaining wall along the length of its region. 

Jeff Bartels Modeling a Civil 3D Corridor with Variable Slope Daylight - https://www.youtube.com/watch?v=NKyTjaUL3J0

[fcernst]

Don't you want Civil 3D to calculate the varying wall height by intersecting a 3:1 slope with the Vertical at each section?

[ndegan]

Fred, 

Yes I think that would be ideal but the connection to EG will constantly change depending on the height of the wall so I don't know of a way to do build a subassembly to calculate in this way. However I was able to put together a subassembly in SAC that does almost everything I want it to. The only thing I don't like about it is I have to specify the height of the wall, which means if I have to use this taper assembly in more than 1 place, I have to create copies to specify the different heights. On this wall I added a generic grade to surface at 3:1.

All things considered I am very excited about this subassembly. I will continue to work on it to see if I can make it more dynamic.

[fcernst]

I want the retaining wall height to taper from the connection to EG, upward to meet the point where the 3:1 assembly and the wall intersect, at a 3:1 slope. ..

Yes I think that would be ideal but the connection to EG will constantly change depending on the height of the wall ..

That's why I was saying don't you want Civil 3D to calculate the height of the wall face at each Section (intersection point up to top of wall). The LinkSlopesBetweenPoints does that, and then SAC has the slope intersection tools.

[ndegan]

I know what you mean and I know that would be preferred, but as I said before, I don't know how to make SAC do that. I know how the link slope to surface and the intersection points work. But to make an assembly change its height or slope over the length of the region takes some interesting arguments in SAC. I only got my wall height to adjust its height by using a subassembly that Jeff Bartels showed in a video for varying slope connections. I took the arguments from that subassembly and modified them to recalculate height of wall. Both situations require user inputs for the starting and ending slope or heights. 

If I created a link slope to surface and then made an intersection point from there, back at 3:1 to where it intersects the wall, the subassembly would be static and the height of the wall would not taper consistently along the length of the region. Which in order to make the wall taper from full to no height, each section needs to update along the length of the region. In other words, the point of connection on EG needs to constantly update to get closer and closer to the wall along the length of the region, then it can calculate 3:1 up to the wall. I don't how to make that happen without having user inputs like the subassembly I currently have, or the original one that Jeff shows.

[fcernst]

but as I said before, I don't know how to make SAC do that...

You use this Tool right here:

[ndegan]

I don't think you are understanding what am saying. Using an intersection point or and auxiliary intersection point will still not update consistently over the length of the region. Not without some other argument telling it to update its connection parameters. Otherwise its static a connection along the length of the region. Your suggestions can all be done with out of the box assemblies, which do not perform the way I need them to.

[fcernst]

Using an intersection point or and auxiliary intersection point will still not update consistently over the length of the region..

Sorry Bud, that's not correct...That's exactly what it's designed to do.

[fcernst]

For example, here is mine going down the region..If the slope projection coming up from the offset (i.e. property line)

starts to shoot up over the wall, I have a Decision that creates a Fill tie-in link to the offset. 

[ndegan]

Yes this method works if you use an offset. It does not work if you want the subassembly to decide its "offset" on its own for each station.

[fcernst]

..The connections to EG (both left and right) are using corridor feature lines as baselines in order to set regions independent of the centerline assembly. This gives more flexibility for placing retaining walls...

So how are you defining the above connections to EG?

[ndegan]

"The attached image shows a trail corridor. 

• The trail and shoulders are 1 assembly using a centerline alignment as the main baseline.
• The connections to EG (both left and right) are using corridor feature lines as baselines in order to set regions independent of the centerline assembly. This gives more flexibility for placing retaining walls.
  • The shown connections are a link slope to surface at 3:1 and a retaining wall. There is no gap in the regions from 3:1 to retaining wall.
• The entire corridor is 5' of fill above EG. "

I am tying into EG using slope to surface and retaining walls on the autocorridor feature lines, which are additional baselines, at the edges of the shoulders. This corridor has 3 baselines (center line, left shoulder, right shoulder). I am not using offset targets for where these assemblies connect to EG.

[fcernst]

You could use a 3:1 LinkSlopeTo Surface from all along the featureline baseline you are using for the 3:1 tie in slope, and pass it’s Offset output parameter as an offset to be used in a slope intersection scheme like I’ve shown. Then Omit the link for production. 

[ndegan]

That wont work for tapering the wall height. The corridor is maintaining 5' of fill, which means if I used a 3:1 link and then had it calculate back to add a wall, the wall would never change height, it would be constant over for the length of the region. 

I'm sticking with the subassembly that I put together as it does what I need. Thank you for your suggestions and work on this thread.

[ndegan · Accepted solution]

@Joe-Bouza @cwr-pae 

I thought Id show you what I came up with for this retaining wall taper. I used and modified the subassembly Jeff Bartels shows in a video for creating a varying slope daylight along a region. Link here - https://www.youtube.com/watch?v=NKyTjaUL3J0 . In SAC I took that subassembly and modified its arguments to vary the height of a point instead of a slope. In other words, I specify the height of the wall at the begining and end of the region, and no mater the length of the region, and it will calculate a varied and smooth height transition along the length of the region.

I created an assembly using my new tapered retaining wall subassembly and then attached a slope to surface link at 3:1. This link could be changed to any slope you are trying to tie into. See attached images.

 

 

[fcernst]

Oh you're manually choosing your taper length...

So, in my slope intersection workflow you would just quickly draw in your desired transition length from the bottom of wall out to the 3:1 (or whatever) daylight slope EG intersection, and target it with the wall subassembly...

There would be no need to create a separate region just for this, then measure the wall height (it won't always be 5', it might be 8.69' next time), then enter your manual starting and ending wall heights.

[Joe-Bouza]

Wow! Just like that you made a sub-assembly? I got the impression earlier you were not acquainted with SAC.

Great for you. cool

[fcernst · Accepted solution]

Another way to do this since you're manually defining the taper length, is to create a simple wall subassembly with a wall bottom target and a daylight slope (i.e., 3:1) coming off of it at the same location, then quickly draw the taper as shown below.

This method again, would not require linear interpolation that involves setting up a separate region, manually measuring the wall, and entering the starting and ending wall heights.

[ndegan]

Thanks Fred,

That would also be a good workflow. Personally, I would rather not deal with maintaining targets if I don't have to. That way if the centerline changes, it doesn't require a ton of target updates. But I'm sure I will end up using both workflows in different situations. The auto-tapering retaining wall would be easier for the trail type projects my company does, where they don't have a lot of restrictions. Your suggestion with a retaining wall with bottom-of-wall target would be a great choice if I needed to to do stepped tapers in the wall or need more control than just a consistent taper, more useful on the roadway projects my company does.

I have built a few retaining wall subassemblies so I will make sure I include elevation targets to them.