Questions:

1. The coefficient of uniformity Cu of a soil is 10 and its coefficient of curvature

Cc is 0.90. You would classify the soil as:

a. Even-graded

b. Medium-graded

c. Gap-graded 6. An oedometer sample had a final water content of 12.5 % and a specific

gravity of 2.7. What was its final voids ratio?

a. 0.338

b. 0.238

C. 1.338

100 9. In a falling head permeameter test the length of the sample is 120mm and its

area is 4417.86 mm². The area of the standpipe is 132.73 mm². At the start of

a test the water level in the standpipe was 410mm and fell to 185mm after

490s have elapsed.

What is the permeability of the soil?

a. 6.16*10-3 m/s

b. 1.25*10-3 mm/s

c. 5.85*10-3 mm/s

ooo 16m

11. An embankment is to be constructed over a 2m thick sand layer, underlain by

a 16m thick saturated soft clay layer, which is underlain by a sand layer. The

embankment will trigger consolidation of the clay layer. For the clay cv-3.1

m²/year. How long will it take for 90% of the consolidation process to be

completed?

0.848

d²=st==

a. 19.8 years

b. 70 years

c. 17.5 years

3.1m

8 m

12.A uniformly distributed Toad of 100 kN/m² is applied on a clay layer. After one

ū

₁s=100& year the average excess pore pressure is 40 kN/m². The average degree of

consolidation of the clay at this time is:

22

a. 40%

b. 60 %

c. It cannot be determined based on the information given

ū=, oni₂

BEng Civil Engineering -Soi Mechanics -May 2022

1:1.

U=

U = Uei- let. 100-

/c 2

7. An oedometer sample had the following voids ratios: e=0.364 under an

effective stress of 0 kPa, e=0.351 under an effective stress of 100 kPa and

e=0.338 under an effective stress of 200 kPa. What is the coefficient of

volume compressibility my of the soil in the range 100 - 200 kPa?

a. 1.9 x 10-4 m²/kN

b. 9.53 x 10-5 m²/kN

c. 9.62 x 10-5 m²/kN

00