Question

What will be the creep settlement of the following soil most likely from one year after the construction to 100 years of construction based on following soil properties?

Cohesion=5 psf, c_α=0.01, void ratio=1.5, layer thickness=10ft

a. 0.02 ft

b. 0.04 ft

c. 0.08 ft

d. None of the above.

You conducted direct shear tests and obtained two test results as follows.

Test 1: Normal stress=0 psf, Shear stress at failure = 3 psf

Test 2: Normal stress=5 psf, Shear stress at failure =3 psf

What will be the internal friction angle of this soil ?

a. 0 degree

b. 5 degrees.

c. 10 degrees

d. 30 degrees

Answer 1

Question 1:

Creep settlement:

where,

= 0.01

ep is void ratio = 1.5

h is thickness of clay layer = 10 ft

t2= 100 years

t1= 1 year

Question 2:

Test 1: Normal stress = 0 psf, shear stress = 3 psf

Test 2: Normal stress = 5 psf, shear stress = 3 psf

here shear stress is constant with change in normal stress thus internal friction will be zero degrees.

If shear stress remain constant that internal friction of soil will be zero degrees.

(1)Creep settlement: 0.02 ft

(2) The internal frictional angle of the soil is zero (0) degree.