Intersection Tin

Nelson Reid · Post by **Nelson Reid** » Fri Feb 23, 2018 9:06 am

I have a new road meeting with an existing. The new road has been designed up to the kerb returns, and the kerb returns designed to marry up to the existing. Now how do I resolve the dead space left in the middle between all these designs. The supertin fills it in, but obviously not to the correct new road pavement. Thanks in advance.

Graeme Winfield · Post by **Graeme Winfield** » Fri Feb 23, 2018 9:53 am

Hi Nelson

Are you taking about the area between the existing road, the kerb return lips and where the new road full section starts?

If so, there is a snippet in the library just for that.
INS_K_INT_PAV_GRADE

Nelson Reid · Post by **Nelson Reid** » Fri Feb 23, 2018 10:26 am

Cheers Graeme

This is my first design so I'm not sure what a snippet is, but I'll see if I can work it out. You have given me some direction.

Owen Thornton · Post by **Owen Thornton** » Fri Feb 23, 2018 11:25 am

For an example without snippets, the Create Roads - Enhanced function does this for you (alternatively, it can also do it with snippets).

It essentially inserts a fixed link named "GRADE" and then applies two separate Fixed - Modify to String modifiers. The 1st modifies "GRADE" to match the lip of the through (existing) road, and the second modifies "GRADE" to match the crown of the side (new) road. The intersection point of the through-lip and the side-crown, is set as the end of the 1st modifier and the start of the 2nd.

Note that the Fixed - Modify to String modifier has now been deprecated by the Fixed - Modify All to String modifier (not sure if Create Roads - Enhanced has yet been updated for that), but they essentially do the same thing.

It looks something like this:

Code: Select all

right_side_modifier = {

  insert "Design>>GRADE" "vis rd bitumen" 0.000000000 unknown 0.000000000 start_ref 0 final_ref 0 absolute extra_start extra_end
  fixed "Design>>GRADE" start_ref 0 intersect_strs "RD STRINGS RS01->KLR" 0 "ALIGNMENT->RS02" 0 0 "RD STRINGS RS01->KLR" 1 absolute extra_start
  fixed "Design>>GRADE" intersect_strs "RD STRINGS RS01->KLR" 0 "ALIGNMENT->RS02" 0 0 final_ref 0 "ALIGNMENT->RS02" 1 absolute extra_end
}

And here is a link to a screenshot of the above:
https://drive.google.com/open?id=17pfX1 ... Tg-zkX0034

Owen.

Owen Thornton · Post by **Owen Thornton** » Fri Feb 23, 2018 11:49 am

IMHO, even if you don't add in the GRADE link and modify it, a triangulation of the two roads and the kerb returns (design strings and x-sections for all) will normally give you a tin that is pretty darn close to the desired finished surface.

Nelson Reid · Post by **Nelson Reid** » Fri Feb 23, 2018 2:41 pm

Cheers Owen

I managed to use snippets, and all is good except that a little triangulation is missing between the new road tin and the kerb return snippet. Can I easily fill this in somehow? Maybe create a dummy point with height for one of these mtf procedures to close the gap and join up the design contour.

Graeme Winfield · Post by **Graeme Winfield** » Fri Feb 23, 2018 2:44 pm

Can you send in an email showing the bit missing from the tin?

Nelson Reid · Post by **Nelson Reid** » Fri Feb 23, 2018 3:11 pm

Thanks Graeme, I have emailed you a couple of images