Question

A 18-ft thick clay layer in the field (drained on one side) is normally consolidated. When the pressure is increase from 0.75 ton/ft^2 to 1.5 ton/ft^2, the void ratio decreases from 1.12 to 0.98. The hydraulic conductivity, k, of the clay during the above loading range was found to be 4.3 times 10^-7 cm/sec. a. How long (in days) will it take for the clay layer to reach 70% reach 70% consolidation? b. What is the settlement at that time (that is, at 70% consolidation)?

Answer 1

a) 294.34 days

b) Δh = 25.361 cm

Step-by-step explanation:

Given data:

Thickness of clay layer = 18 ft

initial pressure = 0.75 ton/ft^2

final pressure = 1.5 ton/ft^2

Δp = 0.75 ton/ft^2

eo = 1.12

e1 = 0.98

k = 4.3 * 10^-7 cm/sec

A ) determine how long it will take to reach 70% consolidation

attached below is the detailed solution

T( time in days ) = 294.34 days

B) determine settlement at 70%

attached below is the detailed solution

Δh = 25.361 cm