uplift pressure on stilling basin floor from hydraulic jump

[bjb]

Can someone direct me to a reference as to how this is calculated? I haven't found anything from the COE or Bureau of Reclamation.

Thanks.

 

[beej67]

If it's not in USBR "Design of Small Dams" then I don't know where it would be.

http://www.usbr.gov/pmts/hydraulics_lab/pubs/manuals_monographs.html

Hydrology, Drainage Analysis, Flood Studies, and Complex Stormwater Litigation for Atlanta and the South East -

http://www.campbellcivil.com

 

[cvg]

the uplift is generally from saturation of the soil.

 

[bjb]

I've read "Design of Small Dams", and don't see a method to calculate this force.

I've read references to an uplift force that results from the formation of the hydraulic jump in a stilling basin, and it is not the uplift force from seepage or hydrostatic head. Unfortunately I can't find a way to calculate this force despite searching through the Corps of Engineers, FERC, and USBR.

I did find an Indian Standard, IS 11527 that has an equation for this force, but the material I was able to download is missing figures that are needed for some of the variables.

 

[Drew08]

NRCS Technical Release (TR) 50 (TR-50)
Design of Rectangular Structural Channels.

http://www.info.usda.gov/

Hydraulic jump, or no jump, stilling basin or chanel, the method is the same.

 

[3feethighandrising]

If it is not in "Design of Small Canal Structures" US Department of Interior-Bureau of Reclamation 1974, I don't know where it would be.

I am unsure how there could be lift, if not from beneath the structure. I do not see a way for water to transmit tension forces on the concrete to lift it from above. There can be a frictional shear of water going up inclined surfaces that points up. This can be calculated if you know the velocity.