Modeling 2 bridges in HEC-RAS at stream confluence

[mricks]

I have a HEC-RAS model for a stream crossing a proposed Interstate (parallel bridges). As it happens the stream is divided under the upstream bridge and comes together between the two parallel structures. By necessity the upstream bridge will need to be larger than the downstream bridge to maintain the low flow conditions. The model runs fine when considering an Energy only approach, however due to the regulations we must run a WSPRO analysis. Every time this is run, no flow is allowed in RAS through the downstream bridge. Any ideas what is causing this?

Thanks

 

[NinetyWt]

How about posting a plot of the cross-sections?

 

[MattZ99]

Have you tried using a Multiple Opening approach for the upstream bridge? You may have to have an extra cross section or two between the bridges.

 

[mricks]

I found it. The problem had to do with the WSPRO analysis being run for the bridges. I copied the cross section I had between the bridges and moved it over a foot to give two sections between the bridges and it worked fine.

Thanks,