HEC-RAS Lateral Structure

[UNHgrad]

I have created a lateral structure in my HEC-RAS model. In the Lateral Structure Editor the graphic does not plot the thalweg profile or show the cross section locations unless I have "Next to left bank station" or "Next to right bank station" toggled in the HW Position pull down. If I have "Left overbank" or "Right overbank" toggled, the graphic shows my upstream cross section location only and holds that thalweg elevation for the entire profile.

I'd prefer to have the lateral structure located at the left overbank. If the graphics (in editor and on geometric plan view) aren't cooperating should I be concerned if it is running the model correctly? Has anyone had this problem?

 

[gbam]

Where is your bank station, physically? I ran into this when I did not have an overbank. Other than that, I do not know.

 

[UNHgrad]

The left overbank station, at my upstream cross section, is about 400 feet left of the left bank station and it tapers to about 70 feet at my last downstream section.

 

[gbam]

Oh, what width in the lateral editor do you have? I usually set the width to 10-feet sdo it shows up in the plan view.

 

[Ryb01]

I'm not sure that I'm understanding your question fully, but from what I gather here are my thoughts;

1) A lateral structure has to be defined bewteen two or more cross sections in the model.

2) A lateral structure, meaning a structure that is perpendicular to the flow or close to it needs to be defined in your cross section accordingly. (i.e. at the right/left OB or next to. Without one of these defined the editor will display the weir/embankment geoemtry as the model has no where to put the data.

3) I believe that all lateral structures are defined starting at the upstream cross section, not the downstream. You can verify in the HEC-Ras manual.

4)Your cross sections should be cut to the limits of the lateral structure, whether the dimension is 400 feet or 70 feet from either station. If you are coding in a lateral structure you are telling the model to divert flow over or through this stucture.


Again not sure if I'm understanding your question, but based on the dialouge so far I think your model is working fine.

Hope this helps.