Ability to Extend SG Slope to Daylight


Is there a way to extend a varying slope to daylight?

For ex. How the offset slope TML works but extending the slope to where it would tie to a surface.

This is a common request in TBC especially for road guys. I know that AutoCAD and Microstation have comparable commands.

Is this possible in TBC? If not… How hard would it be to add a daylight surface tie option to the extend slope TML?

Thanks for your time,

I am not sure which command you are referring to “Extend Slope” TML?

We can chat Monday on this Layne?

Sorry that was an error on my part… Offset Slope

Why would you not use Side Slope for that?

You can add reference lines to sideslope and then use the ref lines to compute the slope (node to node) and have it tie at that slope to existing or whatever surface you want

The slope command does allow that also

Fir subgrades in embankment fills for example you can project a subgrade adjusted slope from eg a pavement out to where it ties to the sideslope of the embankment

I guess the challenge with using side slope is that typically they want to hold the cross slope value which varies when supers are involved, etc.

Side slope you would have to put in the ratio or slope that you want to hold but it would not vary it would just be a static slope percent or ratio. Correct?

I was not aware it worked in that manner.

I thought it relies on 2 lines to determine slope and then you input a distance?

Educate me Mr. Sharp haha

Yes I am open to chatting tomorrow about it.

The videos on the Help Page for each command show how to do this Layne

Here is the link to the Slope Slope one

Click Here

Thank you. I will reference those and figure this out. Thanks so much for your help!


I watched the videos today that you linked. Maybe I missed it but I did not see how you extend a slope to meet a surface?

Ex. Using extend slope to tie to where it meets daylight of another surface.

Is this possible in tbc or with rockpile tmls?

This is basically what I was trying to do…

If you have the strings for the top and toe of the slope of the Finished Surface then the Slope Slope Intersection command will be what you need to use, you pick two strings for the Green surface and two strings for the red surface, and then do a Zero offset vertically for both and it will find you the string where the Green surface ties to the Red Surface on the side slope.

Let me know if you are stuck and I can call you


I did not have the strings for the top and toe… However, I was able to use TMLs to figure this out. I used extend slope to extend the slope of the road well beyond where it would tie on the embankment slope then I used surface intersection to create the line of where the 2 surfaces intersect… remove the line that I used to extend beyond… add all to surface… trim…merge with FG contour surface…

All worked great.

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