Conduit across Concrete Drainage Channel 2

[Bubik]

Hi there everyone.

First of all, I have zero experience with drainage…. I am more from the structural side, but I am required to deliver so…

The contractor was excavating an area for a drainage channel and encountered a conduit with fibre optical cable in it (rerouting of the cable not an option). The position of the conduit would be almost in the middle of the channel cross section. Upstream of the channel section with the cable there is a whole drainage network (not very extensive though) so that all the water from the network flows in to this channel. The channel then meets another drainage network downstream. The project is in the Middle East, not much rain but when it rains it can get heavy for a short time.

Would you guys built a kind culvert, if so would you consult the designer of the drainage system to check if it doesn’t interfere with the water flow and cause excessive water head build up in the system?

One of the guys here suggested casting the conduit in concrete (like a thin beam spanning between the channels walls in the middle of cross section)…. but to be honest I am not sure about it.

Any advice how to approach itt??

Thanks[highlight #E9B96E][/highlight]

 

[oldestguy]

Double posting here is frowned upon. Flag the post and tell the managers to delete any extra posts.

 

[Bubik]

And it will not affect the flow as the cross section area of the channel will be decreased? is it nothing to worry about then?

 

[JAE]

It certainly will affect any flow that is higher than the bottom of the conduit.

I would run this by the engineer who designed the overall channel size. It may be that:
1. You will have to alter the size of the channel (perhaps in the vicinity of the conduit.
2. You will have to check the design of the conduit for lateral fluid flow forces.
3. You will have to design a shroud around the conduit - perhaps wing shaped - to minimize the drag on the conduit and minimize any flow dynamics
4. You will have to consider debris impact on the conduit - tree branches, various debris, floating pieces of trash....similar to what bridge engineers deal with on their piers.



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[Bubik]

JAE

Great Advice. Thank you!!!

 

[cvg]

a "conflict structure" may be constructed to increase the conveyance area at this location and to reduce the impact of debris that might be deposited at this location. Most of these are designed for pipe drains, but could be similar for an open channel. and JAE has it right, this will affect the hydraulics and should be designed by a drainage engineer with structural details by you

examples:

http://www.fdot.gov/roadway/DS/13/IDx/00307.pdf

http://broward.fl.eregulations.us/g...istrative Code/Graphics/images/Exh25A-A21.png

 

[77JQX]

Why is relocation of the conduit not an option? What does the conduit owner have to say about leaving it hanging in space above an open channel?

 

[bimr]

Murphy's Law states that if the conduit is in the flow path, eventually something will hit it.

The cost of splicing a section of fiber optic cable is not expensive and is done all of the time. Suggest you push back on the people that are objecting to moving the cable.

 

[Bubik]

Thank you guys