The moist weight of 0.15 ft3 of soil is 18.6 lb. If the moisture content is 17 percent and the specific gravity of soil solids is 2.62, find the following: (a) bulk density, (b) dry density, (c) void ratio, (d) porosity, (e) degree of saturation, and (f) the volume occupied by water (ft3).

Question

What will be an ideal response?

Answer 1

(a) Solve for the bulk density, using Equation 17.9
? = W / V
? = 18.6 lb / 0.15 ft3
? = 124 lb/ft3
(b) Solve for the dry density, using Equation 17.11.
?d = ? / (1 + w)
?d = 124 / (1 + 0.17)
?d = 106 lb/ft3
(c) Solve for void ratio, e, using Equation 17.13.
e = (((1 + w) (Gs)(?w)) / ?) – 1
e = (((1 + 0.17) (2.62) (62.4)) / 124) – 1
e = 0.543
(d) Solve for porosity, n, using Equation 17.4.
n = e / (1 + e)
n = 0.543 / (1 + 0.543)
n = 0.352
(e) Compute the degree of saturation, S.
S = Vw / Vv = (w)(Gs) / e
S = (0.17)(2.62) / 0.543
S = 0.821 = 82.1%
(f) Determine the volume occupied by water, using Equation 17.7.
w = Ww / Ws
Ww = (w/(1 + w)) W
Ww = (0.17/1.17)(18.6) = 2.70 lb
Vw = Ww / ?w = (2.70 lb)/(62.4 lb/ft3)
Vw = 0.043 ft3