ogee crested weirs

[castro77]

PLS HOW DO I CALCULATE THE VERTICAL AND HORIZONTAL FORCES ACTING ON AN OGEE SHAPED WEIR? ALSO,WHAT IS THE DIFFERENCE BETWEEN EFFECTIVE LENGTH OF A WEIR AND THE REQUIRED EFFECTIVE LENGTH OF A WEIR.WHICH OF THEM SHOULD NE PRODUCED ON A WORKING DRAWING? THANKS.

 

[cvg]

these may help

http://chl.erdc.usace.army.mil/Media/2/7/9/100-c.pdf

http://www.usbr.gov/pmts/tech_services/engineering/design/DS14-1.pdf

show the actual dimensions of the structure on the working drawings

 

[castro77]

Thanks a million cvg.

 

[castro77]

What if i have an ogee shaped weir that is 2meters in height,is it okay to assume a design head of 0.5meters and use the design head to plot out the shape of the weir just like its being done for spillways? Also how do i determine the vertical forces on the weir? being that it will be irregular shaped like a nappe?

 

[cvg]

your forces are hydrostatic, shear and toe pressure
for 2 meter high, velocity is low and shear and toe pressure are fairly low
so the main one is just hydrostatic (weight of the water)

a free body and resolve the vectors to determine the forces

 

[castro77]

Thanks cvg.Should i still design it like an ogee crested spillway oF a dam?

 

[cvg]

its the same thing