Submerged Tank
Submerged Tank
(OP)
I've got a 6' dia tank X 20' long submerged vertically in soil. The x-section of the tank is about 28 ft^2 and the conc base I'm proposing is about 10'X 10'. Assuming the entire system is submerged, is it reasonable to assume that the concrete base has a density of 150-62.4 psf and the included weight of soil is (100 - 28) * (gammasoil-62.4)*20' to resist floatation? or would you neglect the weight of the soil? Assuming no friction along the length of the tank.
Dik
Dik





RE: Submerged Tank
Also, you mention only the base in the weight of concrete. Use the entire structure. Also, your resistive force due to the concrete does not need to subtract the weight of water. That is giving you the net force (Correct for the soil however). Callc the weight of water displaced, and the weight of you structureand soil over the extended footing. Thoose are the two to compare. Add an appropriate FS.
RE: Submerged Tank
Dik
RE: Submerged Tank
RE: Submerged Tank
RE: Submerged Tank
RE: Submerged Tank
Dik
RE: Submerged Tank
The buoyant unit weight of soil is acutally the saturated unit weight of soil minus the unit weight of water. Since the saturated unit weight is defined as the unit weight of soil when it is saturated (obviously), the saturated unit weight should be slightly higher than the moist unit weight, so your calculations should be a bit conservative.
RE: Submerged Tank
RE: Submerged Tank
The flaw in your logic is that you assume that saturated soil offers no resistance to vertical movement. Saturated soil does indeed have strength in the vertical direction.
Ever get your foot stuck in the sand on the beach and try to pull it up without pointing your toes?
RE: Submerged Tank