Hairpin/Horseshoe Bend in HEC-RAS
Hairpin/Horseshoe Bend in HEC-RAS
(OP)
All,
I have a unique situation that I am trying to model. Looking at a culvert replacement that has a sharp bend downstream with most of the inner point bar region in the floodplain. This results in flows going over the floodplain during large storms as well as in the meander bend. In modeling this the flow from each side of the stream will contribute to flooding and inundation in the floodplain and create something like a reservoir effect. My question is can HEC-RAS handle this properly or is a 2 dimensional model (say in FLO-2D) required? Perhaps an in-line weir approach? If so how does the additive flow from the same stream work in HEC-RAS?
I've attached an aerial image to help clarify the issue.
Thanks
I have a unique situation that I am trying to model. Looking at a culvert replacement that has a sharp bend downstream with most of the inner point bar region in the floodplain. This results in flows going over the floodplain during large storms as well as in the meander bend. In modeling this the flow from each side of the stream will contribute to flooding and inundation in the floodplain and create something like a reservoir effect. My question is can HEC-RAS handle this properly or is a 2 dimensional model (say in FLO-2D) required? Perhaps an in-line weir approach? If so how does the additive flow from the same stream work in HEC-RAS?
I've attached an aerial image to help clarify the issue.
Thanks





RE: Hairpin/Horseshoe Bend in HEC-RAS
Good luck with FlO-2D.
With we could do more stream relocalisation... or Expropriation.
RE: Hairpin/Horseshoe Bend in HEC-RAS
Sucks to be that guy who's house is out on the point bar, after you guys remove that culvert and blow the flow through your new bridge. :/
Hydrology, Drainage Analysis, Flood Studies, and Complex Stormwater Litigation for Atlanta and the South East - http://www.campbellcivil.com
RE: Hairpin/Horseshoe Bend in HEC-RAS
Robert Billings
www.newrivereng.com
RE: Hairpin/Horseshoe Bend in HEC-RAS
I have been successful in getting this into HEC-RAS, and used ineffective flow limits to roughly approximate the eddy pools. I may do a quick sensitivity analysis with the ineffective flow settings to bound my results. Thanks for the comments all
RE: Hairpin/Horseshoe Bend in HEC-RAS
Sure you'll need more data but it might be easy to model a short river bend like this one.
As long as it's not an overkill for the project (available money, data).
RE: Hairpin/Horseshoe Bend in HEC-RAS
RE: Hairpin/Horseshoe Bend in HEC-RAS
RE: Hairpin/Horseshoe Bend in HEC-RAS
So far nobody.
Hydrology, Drainage Analysis, Flood Studies, and Complex Stormwater Litigation for Atlanta and the South East - http://www.campbellcivil.com
RE: Hairpin/Horseshoe Bend in HEC-RAS
Grid cells 15 m x 15 m and the program was running for 2 days though.
It's a good alternative to MIKE2D IMO.
Who will pay you for it if you don't need it :)