modelling bridge problems

[bertieboo]

Hi,

I have created a arch in the middle of the upstrema and downstream sections but when i run the model it would appear that the flow uses the entire width of the arch, even though that is not the case due to the ground levels that you can see in the attachment (just to clarify i am talking about the bottom left and right hand corners of the arch that are under ground level, but for some reason when modelled hec ras puts a flow through them)


How can i block these areas of the arch off to restrict flow within the natural channel

 

[gbam]

If you are modeling this as a bridge you can edit the internal cross sections. If you are modeling this as a culvert, I think that it uses the entire culvert geometry unless you use block out in the culvert editor.

You can try hard coding the arch as a bridge with vertical abutments by segmenting the low chord in the shape of the arch. Then the flow would be limited to the Xsec.