3.1. Unified Soil Classification System (USCS)

Question 1

G

Answer 1

Gravel

Question 2

S

Answer 2

Sand

Question 3

M

Answer 3

Silt

Question 4

C

Answer 4

Clay

Question 5

O

Answer 5

Organic

Question 6

Pt

Answer 6

Peat

Question 7

High Liquid Limit (LL > 50)

Answer 7

H

Question 8

Low Liquid Limit (LL < 50)

Answer 8

L

Question 9

Well-graded

Answer 9

W

Question 10

Poorly-graded

Answer 10

P

Question 11

1 ≤ Cc ≤ 3 and 𝐶𝑢 ≥ 4

Answer 11

Well-graded soil condition (gravels)

Question 12

1 ≤ Cc ≤ 3 and 𝐶𝑢 ≥ 6

Answer 12

Well-graded soil condition (sands)

Question 13

Particles larger than 300 mm

Answer 13

Boulders

Question 14

Coarse gravel size range

Answer 14

19mm

Question 15

Particles between 75 mm and 300 mm

Answer 15

Cobbles

Question 16

Fine gravel size range

Answer 16

4.75 mm (No. 4 sieve)

Question 17

Coarse sand size range

Answer 17

2.0 mm (No. 10 sieve)

Question 18

Medium sand size range

Answer 18

0.425 mm (No. 40 sieve)

Question 19

Fine sand size range

Answer 19

0.075 mm (No. 200 sieve)

Question 20

Silt and clay particle size

Answer 20

Smaller than 0.075 mm

Question 21

No. 4 sieve size in mm

Answer 21

4.75 mm

Question 22

No. 200 sieve size in mm

Answer 22

0.075 mm

Question 23

Grain sizes used for Atterberg limits

Answer 23

Silt and Clay

Question 24

What percentage of soil must pass the No. 200 sieve for it to be classified as fine-grained?

Answer 24

More than 50%

Question 25

What soil classification is given when less than 50% passes the No. 200 sieve?

Answer 25

Coarse-grained soil

Question 26

Test used to determine grain size distribution

Answer 26

sieve analysis

Question 27

Plasticity chart is used for these soil types

Answer 27

ML, MH, CL, CH