REV1 RESUB 1 - Bouyancy CalculationBouyancy and Pipe Cover Calculations
Pipe Diameter (D) =
9
feet
Pipe Weight* (W) =
115
lb/ft3
Density of Soil (ps)=
120
lb/ft'
Density of Water (pw) =
62.4 lb/ft'
Pipe Area (AP) =
2
63.6 ft
Bouyancy Force:
Fup= pW*Ar-W
Fup- 3854.7 I b/ft
Required Fill:
Area Required to balance Fup (a) = Fup
PS
a = 32.1 ft2
Solve for Depth (d):
a=A,+A2
Therefore:
a-A2
d= D
d = 2.60 feet
A, = d*D
A 1 D2-17C(D)2
2 2 8
A2 = 8.7 ft2
Therefore use 2.6 feet of minimum cover
* Pipe weight assumes 16 gauge (0.064 inches) steel with Aluminized coating
Pipe information taken from the Washington Culvert Design Catalog pg 58b.