Export to HECRAS tool in Civil 3D 2010

[Anonymous]

I have found that the Export to HECRAS tool within 2010 Civil3D creates an incorrect geometry file. The river/reach line is drawn in the reverse direction, the left and right downstream distances are reversed, and the cross-section stations are reversed.

I created a VBA macro within Excel that corrects the river/reach line and downstream distances in the HECRAS geometry file (*.geo). A new, corrected file is created with "_rv" added to the file name (*_rv.geo).

Additional notes to creating geo files: 
1) You must still reverse all cross-section stations within HECRAS.

2) In Civil3D, you must setup the alignment starting downstream to upstream. Setup left and right banks looking upstream.

3)To force floodplain lengths to be calculated correctly, place banks in the middle of floodplain.

Attached is an Excel spreadsheet that contains the VBA macro.

Scott Stoneman

[Matt.Anderson]

Let me be the first to congratulate you on the effort.

Let me also tell you that HEC-RAS has tools to flip for the cross-section geometry and the reach direction built into HEC-RAS.

[Anonymous]

Hi Matthew,

Thanks for responding to my post. Where do you flip the reach direction in HEC-RAS? I couldn't find that.

Additionally do you agree with how I specified to set-up the alignment and left and right banks in Civil 3D:

- Alignment starting downstream to upstream

- left and right banks looking upstream.

I found no help for setting this up in AutoCAD.

Scott Stoneman

[Matt.Anderson]

When you open the Geometric Data window, find the GIS Tools.   The first item in that menu is Reach Invert LInes Table...

The Flip Coord Order button is on that dialog box.

Downstation is always the bottom of the Reach.  As long as you are consistant with your left-right banks, HEC-RAS  doesn't honestly know the difference and the calculations will be identical as the calculations are not geo-referenced.  The second menu item under GIS tools is XS Cut Lines Table, and it too has a Flip Coordinate order as well.

I typically put my banks where my banks exist to get my channel lenght and banks correct.  The Overbanks are manually set at the centroid of overbank area. 

I have a couple of posts on Civil3d.com on the subject and James Wedding provided a great presentation last year on how to use the HEC-RAS tool during AU.  I would suggest looking that up.

[Anonymous]

Hi Matt,

Thanks for showing me that tool in HECRAS. However, I am still not satisfied with Civil 3D because of the reversing issues. As you mentioned in one of your posts somewhere, the data in the sections will still be reversed. I know that the hydraulic calcs don't make a difference, but it is confusing and isn't good for presentation.

I created another macro that fixes all the problems with the AutoDesk Civil 3D geo file now. I found it fairly easy to manipulate the text files in visual basic.

To use my macro:

1. create alignment stationing from downstream to upstream

2. create sample lines

3. define left and right banks looking downstream

4. use the Civil 3D 2010 export tool

5. use my macro to fix the geo file

6. import the geo file into HECRAS

Everything should be okay!

Scott Stoneman

[Anonymous]

Sorry, here is the updated macro (revision 2).

Scott

[Anonymous]

The macro also works for Civil 3D 2011.

Scott Stoneman

[O.Maille]

Appreciated Scott, I'll try it out when I can.

Like the windes link the hec import/export was a stab at a solution to keep us happy untill the storm and sanitary program is ready, though I don't think the power of hec-ras has been full implemented yet, realistically I don't think it'll be ready untill 2013

[Anonymous]

One more try! Here is an updated and renamed macro.

I noticed the macro didn't work on another computer at my office. So, I removed the embedded connections to some unnecessary DLLs.

Scott Stoneman

[Hidden_Brain]

along the lines of the same topic:

i set up my cross section cut lines in C3D, cut the sections, export the .geo file, import it into HEC-RAS, and flip the reach coordinates and the cross sections, everything works fine and dandy. now if i run RAS and find out cross sections where i have the "wall" warnings, i need to extend them. i have been getting away with draping a feature line, then adding its X-Z to hec-ras, but would like to hear if others are following a more of an "automatic" way. also, if i have conveyance or velocity head warnings, i have to go cut additional sections. how is everyone tackling those issues with the ras extension?

[Anonymous]

That method sounds fine if you have put a lot of time into the HECRAS model since the original geo file import. However, I think its best to check the "wall" condition and if additional sections are needed straight away. If so, then go back to the original alignment in C3D and extend and add sample lines as needed, recreate a new geo file, and re-import into HECRAS.

[Hidden_Brain]

you are right; the problem i have is when i have structures, storage areas, ineffective flows etc all keyed in, then i re-run and get warnings/notes that warrant additional cross sections and/or extensions. then, i am too far along (as you mentioned) in the hydraulic model to turn around and start afresh, with a new geo file.

[Matt.Anderson]

I hope you realize that HEC-RAS GIS import has Update / Merge ability...

[Anonymous]

Eventually, we will be able to cut our sections within the HECRAS RAS Mapper. See link below. I copied page 25 that lists future improvements.

http://www.same.org/files/public/JETC2010-Session4-Track4.pdf

Future Improvements
Export to KML –Visualize in Google Earth
Image support - MrSid, jpg, tiff …
Additional output - Temperature, sediment, arrival time and duration grids
Improved interpolation
Delineation of backwater areas
Data formats (TIN, grid)
Geometry data creation/extraction/development
Improved computational performance

But, until then we can use C3D or ArcGIS.

[mikem]

I'm surprised noobody else chimed in here. It is incorrect that sections should increase station from right to left as if you were looking upstream, as is standard with road design. In HECRAS,sections are viewed looking downstream. So for instance section station 0 would be on the left with increasing staionting (X values) to the right.

You are correct that centerline stationing startts at the downstream end.

[Anonymous]

Not sure what you are talking about.

All I am trying to do in this post is share a macro I created in Excel that fixes the incorrect geo file that Civil 3D creates.

Scott

[mikem]

Sorry. I  misunderstood your initial explanation. My comment is addressing one of your early posts where you state  "Setup left and right banks looking upstream" and later,"- left and right banks looking upstream". I'm a hydraulic engineer and I frequently need to explain to road engineers that in HECRAS, the section geometry and associated left and right bank stations are viewed looking downstream. Therfore, the x-axis values on a cross section view should start at "river-left" looking downstream (or down the centerline). The road guys and gals are sometimes used to reading sections as if looking up the centerline, or toward increasing centerline stationing. I jumped to that conclusion with your post.

I realize now that i missed the point, and that your macro fixes centerline reach coordinate order, and that you do explain that the section stationing still needs to be reversed in HECRAS, and which is later explained to be also fixable within HECRAS.

We have been using GEORAS with GIS to export the geometry files that include bank stations, overbank reach lengths and even roughness zones, so I admit I havent used the CAD tool. I'll give it a shot. It will be nice to export my own files without having to pin down the GIS tech. Thanks for the macro.

[Anonymous]

I am totally in the same situation as you, as I think are a lot of other HECRAS users. I have access to Civil 3D, but have to go through the GIS department to use HECGeoRAS.

I think that Autodesk got the whole HECRAS thing (reversed stations) wrong because they are road designers.

If you do use the macro, use my instructions from Message 5 and download the macro from Message 9.

Cheers,

Scott

[Hidden_Brain]

since this thread came back to life, i decided to throw out another question for all the "gurus". anyone has a trick up his/her sleeve about how to get the deck high chord elevations automatically for your bounding cross sections?

[Anonymous]

what do you mean by the "bounding cross-sections"? Do you mean bridge section? Are you asking how to get the section data from a bridge deck from C3D into the HECRAS bridge high chord table?

If so, I don't think you can do it automatically. I would just cut a section in C3D and cut and paste the tabular results from C3D to HECRAS. Hopefully, you don't have too many bridges.