People ignore scour, people ignore subsidence/sealevel rise/severity increase/etc. The problem is that everyone intentionally skirts those codes. wet and in need of finishes, but standing. If you were in an ICF house of piers 2' above the design flood, your house would probably still be standing when it got slammed with 8 extra feet of water. I think that you should have to design for a reasonable probability. I think that building in flood plains should be allowed. RE: density of riverine flood water asabender (Structural) Right now I'm just conservatively using 64.0 for the inbound water. I know that that bank could be mostly gone after the flood. I know the 'sediment' load I'm going to add within the building from the fraction which could be hazardous material. With the backflow prevention, this means I will be pumping the building up like a balloon and dealing with the hydrostatic forces. I'm putting an ACE design-basis scour apron in the area. The vents have to protrude through the adjacent embankment to get the right elevation and invert clearance. I need the vents because I don't have a reasonable factor of safety over floatation. 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. Have you ever heard of a sediment load getting it higher than 63 for a riverine flood? Good point on the n value, but my situation is hydrostatic.

My intake vents protrude less than 18' from soil which could suspend and intake.Īll 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 cvg (Civil/Environmental) 8 Aug 17 22:35 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. I'm in a much smaller river than the CT River with a much higher velocity. Those fractions of a pound add right up with my considerations, and those values are not overly conservative. 4000, which I would think to be, perhaps, moderately conservative, gets me 62.82 pcf.

For consideration, if I presume that my my flood event runs 2000 mg/l my unit density will be 62.61 pcf. I will clearly have more sediment than that. The entire Connecticut River ran 780 mg/l (62.5 pcf) in a less severe flood event, measured in its estuary.

Water density in lbft3