Question

B. A constant-head permeability test was run on a soil sample 7.3 em in diameter and 14 em long, Q-10 em/min, b-100 em. The soil grains have a dry weight of 985 g, a specifie gravity of 2.7, and a void ratio 0.610. Determine the followings a. The coefficient of permeability. b. The seepage velocity of the soil v. 15 c. The actual velocity v. 4c

Answer 1

d = 7.3cm, l = 14cm, h = 100cm Q = 10cm^3/min, W_d = 985g, G = 2.7 e = 0.61 hydraulic_(1) gradient = h/l 100/14 = 7.1428 we know Q = k times i times A or 10 = K times 7.1428 times pi/4 times 7.3^2 or K = 0.03345 cm/min or K = 5.575 times 10^-4 cm/s we know V_s = Ki or V_s = 5.575 times 10^-4 times 7.1428 or V_s = 3.9821 times 10^-3 cm/s we also know V_a = V_s/eta, where x rightarrow porosity eta = e/1 + e = 0.61/1 + 0.61 implies n = 0.3788 therefore V_a = 3.9821 times 10^-3/0.3788 implies V_a = 0.01051 cm/s