Pavement leveling

[starki83]

Hello guys. If anyone could help me with following

Survey team recorded 2000 profiles (20 km of road) each cross section in 5 points. We created tin model of road and made 2000 profiles, one profile each 10m.

Now the condition of existing road is really messed up, it hasn't been repaired in 40 years. Basically there are 2 main cases of cross sections on existing road (98% belong in these two cases), concave and convex.

For case 1 i figured out how to  easily get orange line from black line (which is survey) and area between them (area between black and orange lines in each section will get me volume of needed asphalt for leveling before new asphalt layer with constant width). But the problem is case 2 from drawing.

I can easily get green line with weed lisps, but i actually need a lisp or some other idea to get this orange line. Orange line is weed from black line but moved upwards so the point on black line which is furthest from green line will belong to orange line. Orange line is paralell to green line. So position of orange line is what i need. Anyone any help please?

 

[BIGAL]

I have been doing this for like 40 years and at the end of the day you must make decisions manually about final levels. My recommedation "Civil Site Design" its road rehab routines are brilliant which is what your trying to do. This has been in the software for more than 30 years.

 

www.civilsitedesign.com.au

Edited February 28, 2019 by BIGAL

[starki83]

Thank you Bigal very much. I will take a look at it. I figured one way which is pretty simple but not as accurate, but it gives me a rough idea of needed asphalt for leveling layer of rehabilitation. I use autocad command close polyline no mater if it is concave or convex than calculate areas and volume. If the black line would be consisted of 3 lines (it would be triangle area. ) it would be perfectly accurate. But since it is made of 5 it makes a small error. Now other problem is that  by doing this way you actually mess up profile of axis.

[marko_ribar]

There are 2 ways that comes to my mind... First and much simple is that you use UCS to align Xaxis to connecting 5th line, then you transform all objects from UCS to WCS using (tranformby) function with supplied matrix for transormation... Then when in WCS you use (vla-getboundingbox) method to get lower left and upper right points, then you apply WCS to UCS transformation like nothing has happened after you selected your lines - pline and finally you do RECTANG command in UCS, but with points obtained from WCS...

Second method is little picky, you have to assume that you know where is one outside point from side of pink line... Then you use (vlax-curve-getclosestpointtoprojection blacklw pinkpoint normalvector-which-here-it-is-closing-direction-5th-line) and you should get point that is touching blacklw from top side, then you entmake one parallel line from closing 5th line in vector opposite than you get from obtained point on blacklw and point (inters pointonblacklw (polar pointonblacklw (+ (angle stpt5thline enpt5thline) (* 0.5 pi)) 1.0) stpt5thline enpt5thline nil)... So this opposite vector is all you need to get stpt of orange and enpt of orange (setq stpt (mapcar '+ stpt5thline oppvec)) and (setq enpt (mapcar '+ enpt5thline oppvec))...

 

I am sure there may be even more ways, but those are my preferances...

Hope this helps, M.R.

[BIGAL]

Mrako_ribar whilst your answer is more than likely very good for each cross section you have to remember that this is a road task. We take the left and right road edges apply grades and vertical curves to the two egdes and then for this example grade between the two lines. So you have to re-do, re-do the edges coming up with the best fit. Either planning the existing road or adding "regulation" to fill in hollows. Vertical curves could be 40m long but you have crossections at 10m. 

 

From this you can work out profiling areas as asphalt has to be say 25mm thick minimum. You can work out the regulation volume and the top asphalt volume.

 

As I said this was a every day task for our unit, to add to the complication we would introduce wandering crown lines to minimise cross grades, this may become applicable in the task by the OP as the image clearly shows a height difference between left and right.

 

There is some lisps for road gradings so you could work out a z for each crossection and work out areas/vols.