Suspended Solids
Suspended Solids
(OP)
Does the added weight of silt carried in a river increase the density of the water in a significant fashion?
I'm looking at a coffer dam design and the engineer from another office has used 62.43 for the density. I usually use 62.4 (62.42 is the greatest density for 4 degC), and I was wondering if this extra .01 pcf would account for silt in the flow. The amount of silt load is fairly heavy (Red River (North)).
The precision isn't an issue, I just want to get a bit of a handle on the increased density for better understanding.
Thanks, Dik
I'm looking at a coffer dam design and the engineer from another office has used 62.43 for the density. I usually use 62.4 (62.42 is the greatest density for 4 degC), and I was wondering if this extra .01 pcf would account for silt in the flow. The amount of silt load is fairly heavy (Red River (North)).
The precision isn't an issue, I just want to get a bit of a handle on the increased density for better understanding.
Thanks, Dik





RE: Suspended Solids
I'd bet you're just looking at a typeo, unless the water's brackish, which does change the density.
Hydrology, Drainage Analysis, Flood Studies, and Complex Stormwater Litigation for Atlanta and the South East - http://www.campbellcivil.com
RE: Suspended Solids
Dik
RE: Suspended Solids
http
assuming a dry unit weight of 100 pcf for the silt, you would need just 0.08% silt per cubic foot of water to increase the weight to 62.43. However, I have not seen the density of water ever changed from 62.4 for a hydraulic or structural analysis. I would be more inclined to assume some deposition of silt at the base of the cofferdam rather than assuming any change to the density of water.
RE: Suspended Solids
Dik
RE: Suspended Solids
/grin
Hydrology, Drainage Analysis, Flood Studies, and Complex Stormwater Litigation for Atlanta and the South East - http://www.campbellcivil.com
RE: Suspended Solids
RE: Suspended Solids
I agree; I try not to design anything that tight...
Hokie:
same here...
thanks, gentlemen
Dik