×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Bridge Modeling vs Culvert Modeling for bottomles culverts...

Bridge Modeling vs Culvert Modeling for bottomles culverts...

Bridge Modeling vs Culvert Modeling for bottomles culverts...

(OP)
In cases where there is stream grading (especially in cases where there are low flow channels in the stream) occuring what would be the reasons for using Bridge modeling approach instead of culvert modeling for a 3 sided bottomless structure? I'm noticing that design criteria is being created based on overall flowrate and not stream conditions. In other words if you hit a certain threshold of discharge for the design storm then you are forced to design the structure a certain way.  

Wouldn't the culvert options give you better data input for the stream, roughness coefficients, roadway input, actual culvert input?   

The Bridge modeling approach forces you to make the culvert length the same as the roadway width even though that might not be the case.  Plus wouldn't the concrete in the upper part of the arches have an effect on WSE as does the stream grading conditions and protections that are going to be used?

I just curious how y'all are modeling these structures.

RE: Bridge Modeling vs Culvert Modeling for bottomles culverts...

Around these parts, anything 20' or greater span is a bridge and smaller structures are analyzed in HY-8. I haven't looked much into it in the Hydraulic Reference Manual, but when I modeled culverts before I got vastly different results to stage-storage hydrograph analyses.  That was with pressure flow conditions, though.   

RE: Bridge Modeling vs Culvert Modeling for bottomles culverts...

the way I see it bridge modeling is best for low flow conditions as it factors in the xscc shape within/under the bridge.  Once the inlet becomes submerged then there should be no/little difference in the hydraulics.  As to the length, in HECRAS you can set the length of the bridge seperately from the road width using distances to upstream xsec.   

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources