density of riverine flood water
density of riverine flood water
(OP)
I am trying to design a hydrostatic retention system for a riverine flood. I know the elevations and flow volumes during the design flood event, taken at the location, which is a real event from 2010 exceeding the FEMA 100 year flood. The project area is in a still water zone. I am trying to find an adequate value for the unit density of such water. I know that the CT river had a maximum sediment load of 780 mg/l. FEMA was no help. Any suggestions for a unit weight of riverine flood water?





RE: density of riverine flood water
RE: density of riverine flood water
I'm in a much smaller river than the CT River with a much higher velocity. I'm on an interior re-curved bank within a mile of an outfall, all of which got chewed up (trees, concrete and all) during the flood event I'm designing for. My intake vents protrude less than 18" from soil which could suspend and intake.
All other considerations aside, does anyone have a reasonable value of unit weight or sediment load for a 150 year flood in a bendy little river which usually passes 2k CF passing 30k CF during the flood?
RE: density of riverine flood water
without giving any data, how could anybody possibly give you a good value for the sediment load of an unnamed river?
RE: density of riverine flood water
It's a strange job. The vent is a "flood vent" but with a 1 way valve on it (backflow preventer), because we don't want the hazardous material coming back out of the building. I need the vents because I don't have a reasonable factor of safety over floatation. The vents have to protrude through the adjacent embankment to get the right elevation and invert clearance. I'm putting an ACE design-basis scour apron in the area. With the backflow prevention, this means I will be pumping the building up like a balloon and dealing with the hydrostatic forces. I know the "sediment" load I'm going to add within the building from the fraction which could be hazardous material. I know that that bank could be mostly gone after the flood. Right now I'm just conservatively using 64.0 for the inbound water.
RE: density of riverine flood water
http://files.engineering.com/getfile.aspx?folder=d...
RE: density of riverine flood water
RE: density of riverine flood water
RE: density of riverine flood water
I think it's pretty clear after Harvey that the ones in Texas are very wrong, and the ones in Louisiana are likewise very likely to be deeply flawed.
Hydrology, Drainage Analysis, Flood Studies, and Complex Stormwater Litigation for Atlanta and the South East - http://www.campbellcivil.com
RE: density of riverine flood water
Dik
RE: density of riverine flood water
RE: density of riverine flood water
The problem is that everyone intentionally skirts those codes. People ignore scour, people ignore subsidence/sealevel rise/severity increase/etc. In New England, where I am, people don't remember a big storm. If you find some centenarian, they may remember the Long Island Express of '38, but people just don't realize that THAT isn't as big as our design storm. We haven't been hit hard since the 1600's. I constantly work on mega mansions that are dipping their toes in the atlantic, skirting all the design codes by jumping from the unclear and crappy IRC to municipal codes.
RE: density of riverine flood water