Lecture 2 - Factual and Interpretive Reporting Flashcards

1
Q

What does BS5930: 1999 indicate?

A

Basic principles of how rocks should be described

Particular order

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What three decisions must be made for soil descriptions? (NOTE: Opposite from order or words)

A

Principal soil type
Secondary and minor fractions
Other features

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

How do you distinguish silt from clay using the dry strength technique?

A

Roll a moistened sample into a thread/ribbon
Air dry
Crumble
SILT will crumble easily, CLAY will not

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

How do you distinguish silt from clay using the dilatancy technique?

A

Place sample in one hand, palm up
Add water to form a putty
With empty hand, pat sample hand for 5-10 secs
If water rises to surface = SILT

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what two types of laboratory tests are undertaken and what do they test for?

A

Geotechnical - classification, shear/compressive strength

Environmental - sulphate, pH, metals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

How is moisture content worked out? What happens to sample before test?

A

Sample dried in oven

p=(W-D)/D

p = fraction of total evaporable moisture content of sample, W = mass of original sample,
D = mass of dried sample
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

How is particle size distribution carried out?

A

Sieve analysis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are Atterberg limits?

A

Depending on water content, soil is solid, semi-solid, plastic or liquid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is meant by plastic and liquid limit?

A

Plastic limit = where soil becomes plastic

Liquid Limit = where soil becomes liquid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the plasticity index? How is it worked out?

A

Measure of plasticity

Its difference between Liquid limit and Plastic limit

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Give an example of a chemical classification?

A

pH

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

How is the California bearing ratio calculated? What does it measure?

A

Measures compaction

Pressure to penetrate soil sample with standard plunger, divided by pressure to penetrate a standard crushed rock

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

How is shear strength calculated?

A

Unconfined compressive strength

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

How does uniaxial shearing occur? What does it measure?

A

Soil sample cylinder compressed between two plates

Measures maximum load at failure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

How is shear strength of soil tested under controlled drainage conditions?

A

Triaxial test

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

During a triaxial test what is the specimen subjected to?

A

Confining fluid/air pressure

Loaded axially to failure

17
Q

Why is it called triaxial test?

A

3 principal stresses known and controlled

18
Q

What is major principal stress (o1) the sum of?

A

Applied axial stress (^o = P/A) + chamber (confining) pressure (o3)

19
Q

What is the intermediate and minor principal stresses? How are they similar?

A

o2 and o3

They have identical values

20
Q

How are soil, groundwater and soil leachate collected for chemical testing?

A

Soil - disturbed samples
Groundwater - directly collected
Soil leachate - subject to leaching in lab