Water pressure on weir

[P713]

I'm wondering if anyone can advise me on the following, regards water pressures exerted on a low overflow intake weir for a 'run of river' hydro scheme.

The elevation of the weir crest in question is pre-determined by existing pipework. This results in the base of the downstream collection chamber (built into the weir) being for the most part below (up to 1m) the level of bedrock forming the stream bed.
My question regards the water pressures exerted on the structure:-
Assuming that the structure is cast onto the bedrock at the bottom of the excavation and the space between the structure and the remaining bedrock is backfilled with mass concrete up to original streambed level, are there any water pressures exerted on the parts of the structure below the top of the mass concrete?

 

[dicksewerrat]

Pressure on the weir is depth of water x unit weight of water.

Richard A. Cornelius, P.E.

http://WWW.amlinereast.com

 

[RWF7437]

No

 

[cvg]

if there are any cracks, then water can seep down to the foundation and exert full hydrostatic pressure. Generally, this should be assumed to happen