cofferdams 9suspended solids question0
 

cofferdams (suspended solids question)
does anyone know how to calculate the relative density (specific gravity) of water with 40,000 ppm of suspended solids (fine silts).
this is not structural question, but i would assume structural engineers that design cofferdams in rivers may have encountered this before.
vod

try (40,000/1,000,000(150 pcf)+ 960,000/1,000,000(62.5 pcf))/62.5 pcf.
jedclampett got you pretty close. he used a specific gravity of 2.4 for the silts (150/62.4). the specific gravity is closer to 2.7.
the corrected equation is:
40000/1000000*(62.4*2.7)+960000/1000000*(62.4)
which yields a value of almost 67 pcf. that's pretty thick stuff.
(the equation above can be copied straight into excel.)
outdone again :)
regards
vod
you could use a cheap hydrometer with a sample of the material.
yeah, but calculating it is so much fun!