Soil Classification

Question 1

Wentworth scales are used for what purpose with what type of rock?

Answer 1

Classification of seds and sedimentary rocks in clastica

Question 2

Describing soils in the field should include:

Answer 2

1. Main sed type (all caps)
2. Minor components (lower case)
3. colour (adjective)
4. Moisture content (dry, moist)
5. Consistency (soft, stiff)
6. Density (coarse grained only)
7. Geologic origin (fluvial, glacial till)
8. Foreign material (concrete)
9. Odour (HC odours)
10. Presence of contaminants (HC staining soil)

Question 3

If the jar test produces 3 distinct layers then what is present?

Answer 3

Sand silt and clay

Question 4

How do you name jar test soils

Answer 4

Using usda soil texture triangle

Question 5

What sieve range is sand

Answer 5

10- 200

Question 6

What is used to separate silt and clay after a sieve test?

Answer 6

Hydrometer

Question 7

Calculation for % retained in a sieve test

Answer 7

% retained = m sieve /total mass x 100%

Question 8

Calculation for % finer

Answer 8

% finer = 100- sum of % retained on sieve and above

Question 9

Classification of fine grained soils is based on:

Answer 9

1. Grain size

2. Plasticity

Question 10

What does cohesiveness describe?

Answer 10

The ability of a soil to be reshaped in the presence of some moisture, without crumbling

Question 11

What % of clay does soil need to be cohesive?

Answer 11

8-12 %

Question 12

At low and high moisture content how of cohesive materials

Answer 12

Low moisture - solid

High - liquid

Question 13

Are consolidated sediments affected by water content?

Answer 13

No

Question 14

Define plastic limit

Answer 14

PL

The moisture content (%) of a soil at which it will crumble when rolled into 1/8 inch diameter threads

Question 15

Define liquid limit

Answer 15

The moisture content (%) of a soil required to close a distended of 0.5 inches along the bottom of a groove after 25 blows