bug in hec-ras 6

[mab aba]

Hi I tried to run a 2d hec-ras model v6.3.1 using 60 bridges and I got this error:
Plan: ‘Plan009’ (MAS2Dv01.p04)
Simulation started at: 04Apr2023 08:42:55 AM

Writing Geometry…
Computing 2D Flow Area ‘MAS2D’ tables: Property tables do not exist.
2D Flow Area ‘MAS2D’ tables complete 446.65 sec
Completed Writing Geometry

Geometric Preprocessor HEC-RAS 6.3.1 October 2022
An error occurred while reading 2D bridge

Review your data at this location for completeness and consistency
An error occurred while reading 2D bridge

Review your data at this location for completeness and consistency
An error occurred while reading the culvert hydraulic table information
at river station in reach
Review your data at this location for completeness and consistency
Error Accepting the preprocessor files.

Computations Summary

Computation Task Time(hh:mm:ss)
Completing Geometry 7:31
Preprocessing Geometry <1
Complete Process 7:31

I can’t see which bridge has a problem in the error message

Any help?

thank you

[Chris Goodell]

Do any of your bridges happen to be named “2D bridge”? If so, that’s the one.

[Luis Partida]

@Chris, this is actually a much more complex issue than you have presented.

Geometric Preprocessor HEC-RAS 6.3.1 October 2022
An error occurred while reading 2D bridge

When RAS says “2D Bridge” as the error message than the HDF has become corrupt I believe as the error occurs in preprocessing from geometry to HDF. You can delete bridges one by one until the errors go away but then you still cannot rebuild the bridges. You can even try saving the geometry as which then assigns it a new .gx extension which also will populate the temp .gx HDF then ultimately transfers to the final geometry HDF. But this still does not fix the issue. I am still not sure how to fix this issue and am working with a colleague on a solution. Here are processes I have tried with no success:

-creating a new RAS model and importing the geometry into a new domain
-naming the “problem” bridge a new name (if you have found it…also note that it is random and nothing is actually wrong with the found bridge)
-deleting bridges one by one, then manually rebuild each (you will still hit a wall once RAS creates the problem)
-trying alternate locations of storing the model, diff path names (it was built and ran on my local drive)

This is also specific to bridges. If you add a culvert no error occurs, such that if you find the problem bridge and just convert it to a dummy culvert the model will run.

If anyone has any other ideas please let me know.

[Luis Partida]

SOLUTION:

Thanks to brainstorming with my colleague Myles….The issue was that the problem bridge(s) had lengths that were shorter than the cells it was connected to.

For example, I had a bridge that’s CL length was 50 ft based on the drawn connector line. The overall spacing was 200x200ft with refined spacing of min 100 and max 150ft. Well RAS does not like this, so rule of thumb is that RAS reports ghost errors in saying “2D Bridge…” and will not identify the actual structure with the issue when the CL length of the structure is less than the cells it is connected to.

[A Atkinson]

Hi Luis (and others) – how did you end up solving this problem? I am having this issue too. I’ve tried lengthening my bridges using the Move Points tool and by adding additional length on the Deck Editor. The ends of the bridges appear to line up with cell borders. Do you just have to delete and recreate the bridges?

Thanks!

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