Grading Question

[darreng_oa]

Having many issues using the grading tools, so will do my best to ask the questions in a logical order.

I have been tasked to compute volumes between a recent topo survey and a design grade channel with side slopes (mostly 6:1).  Everthing works great if I create a single Grading Group (gg), but further instructions given now want volume calcs and certain reaches (every couple 100 feet) and here is where I lose it: I decided to simply re-build grading groups at the desired stationing, but the resulting gg are very "messy" at the transition points: sharing of contours, gaps in the surface, etc.  One fix, was to start the next gg fractions of inch away from the previous gg, which, on the straigt sections, worked great.  I guess what I am trying to ask, is why does C3D "connect" grading groups that built adjacent?

hope this makes a little sense, and appreciate any insight!

cheers, oa

[Joe-Bouza]

this is what I would do. make one complete grading group like you started with, then create a surface for each reach, paste the GG surface into them and add a clip boundary for the desird reach

[neilyj666]

Adjacent grading groups in the same site will interact by default.

I would model the whole channel and use Volumes dashboard to isolate particular areas.

A corridor modelling approach might be a better option than "buggy" grading groups.

[darreng_oa]

unfortunately, i cannot appy a single GG. there are reaches now with varying slopes and even more complex design features (turning basins, flat areas). Perhaps Grading Tools is not the best fit for this job?

[Joe-Bouza]

Right. thats what neilyj meant in line 3 of the post

[neilyj666]

Take a look at this http://bimontherocks.typepad.com/my_weblog/2009/10/leveraging-a-temporary-corridor-for-stream-projec...

[Neilw_05]

Could you post a screen shot showing your project? It would help.

[darreng_oa]

sorry to leave this post hanging.  I am still trying to learn the Grading Tools, and think posting any more questions might create more questions than answers.  The learning curve is getting less, but still plunking away!

[neilyj666]

keep asking; we were all at the plunking away stage once too...