Lesson 2: Physical Properties

Question 1

It is composed of solids, liquids, and gases

Answer 1

soil

Question 2

it may be minerals, organic matter, or both.

Answer 2

solid phase

Question 3

the spaces between the solids (solid particles)

Answer 3

voids

Question 4

_____________ is the predominant liquid and ______________ is the predominant gas.

Answer 4

Water, Gas

Question 5

The soil water is called the ___________ and plays a very important role in the behavior of soils under load.

Answer 5

porewater

Question 6

If all voids are filled with water, it is ___________

Answer 6

saturated

Question 7

If no water in the void space, it is _____________

Answer 7

dry

Question 8

If the void is partially filled with water , it is ___________

Answer 8

moist

Question 9

The physical parameters of soils are influenced by the
relative proportions of each of these phases. (True or False?)

Answer 9

True

Question 10

The ratio of the amount of water (Ww) in the soil
(Ws) and expressed as a percentage.

Answer 10

Water Content, w

Question 11

The ratio of the volume of void space (Vv) to the volume of solids (Vs). It is usually expressed as a
decimal quantity.

Answer 11

void ratio, e

Question 12

The volume of soil per unit volume of solids. This
equation is useful in relating volumes.

Answer 12

Specific Volume, V’

Question 13

The ratio of the volume of voids (Vv) to the total
volume (V).

Answer 13

porosity, n

Question 14

The maximum and minimum porosities would be ______ and _______, respectively

Answer 14

48% and 26%

Question 15

The maximum and minimum porosities stated is equivalent to maximum and minimum void ratios of _______ and _______, respectively.

Answer 15

0.91 and 0.35

Question 16

The void ratios of real coarse-grained soils vary between _________ and _______

Answer 16

1 and 0.3

Question 17

Clay soils often have void ratios greater than 1. (True or False?)

Answer 17

True

Question 18

The ratio of the volume of water to the volume of
voids, often expressed a percentage.

Answer 18

Degree of Saturation, S

Question 19

If S=1 or 100%, the soil is ____________.

If S=0, the soil is _____________.

Answer 19

1. saturated
2. dry

Question 20

The weight of soil per unit volume (bulk unit
weight/ moist unit weight)

Answer 20

Unit weight, y

Question 21

Special cases in unit weight

Answer 21

1. Saturated unit weight
2. Dry unit weight
3. effective or buoyant unit weight

Question 22

Considering the limits of unit weights for soils, we will use the ratio of the soil’s unit weight to that of water. This ratio is a dimensionless quantity label as _____.

Answer 22

Rd (unit eight ratio or density ratio)

Question 23

This is an index that indicates the degree of packing between the loosest and densest possible state of
coarse-grained soils as determined by experiments.

Answer 23

Relative Density, Dr

Question 24

This is similar (not identical) to relative density (Dr)

Answer 24

Density Index

Question 25

This is a ratio of the volume of excavated material to the volume of in-situ material (sometimes called borrow pit material or bank material)

Answer 25

Swell factor (SF)

Question 26

The physical and mechanical behavior of fine- grained soils is linked to four distinct states:

Answer 26

solid, semisolid, plastic, and liquid, in order of increasing water content.

Question 27

Point A – original liquid state. As the soil dries, its water content reduces and so does its volume. Point B – the soil becomes so stiff that it can no longer flow as a liquid. The boundary water content at point B is called the liquid limit; it is denoted by _____

Answer 27

Liquid Limit (LL)

Question 28

Point C – the water content at which the soil changes from a plastic to a semi-solid is known as the ___________

Answer 28

Plastic Limit (PL)

Question 29

If drying is continued beyond the range of water content for plastic behavior, the soil becomes a ______________.

Answer 29

semisolid

Question 30

The range of water content over which the soil deforms plastically is known as the __________

Answer 30

Plasticity Index, PI = LL-PL

Question 31

As the soil continues to dry, it comes to a final state called the _________. At this state, no further volume change occurs because nearly all the water in the soil has been removed.

Answer 31

soild state

Question 32

Point D – the water content at which the soil changes from a semisolid to a solid is known as _________

Answer 32

Shrinkage Limit, SL

Question 33

The range of water content from the plastic limit to the shrinkage limit for which the soil behaves as a semisolid is called the _______________

Answer 33

Shrinkage index, SI = PL-SL

Question 34

He developed a method to describe the consistency of fine-grained soils with varying ω.

Answer 34

Albert Atterberg, 1911

Question 35

Index parameters are:

Answer 35

a) Plasticity Index (PI= LL-PL) b) Liquidity Index (LI = ω-PL / LL-PL) c) Shrinkage Index (SI= PL-SL)

Question 36

It is the moisture content after 25 blows or moisture content at which a soil changes from the liquid state to the plastic state.

Answer 36

Liquid Limit (LL)

Question 37

The liquid limit is determined from an apparatus that consists of a semispherical brass cup that is repeatedly dropped onto a hard rubber base from a height of 10mm by a cam operated mechanism. The apparatus is called _________

Answer 37

Casagrande Cup

Question 38

It is a moisture content in percent at which the soil crumbles, when rolled into threads of 3.2mm (1/8”) in diameter.

Answer 38

Plastic Limit (PL)

Question 39

-it is the relative consistency of a cohesive soil in the natural state. -ratio of the difference in water content between the natural or in-situ water content of a soil and its plastic limit to its plasticity index.

Answer 39

Liquid Index, LI

Question 40

_______________ or simply consistency is analogous to viscosity in liquids and indicates internal resistance to forces that tend to deform the soil.

Answer 40

soil consistency

Question 41

The internal resistance of soil may come from inter-particle forces (cohesion or adhesion), cementation, inter-particle friction, and soil suction. (True or False)

Answer 41

True

Question 42

Consistency changes with water content (True or False)

Answer 42

True

Question 43

A measure of consistency is provided by the __________

Answer 43

Consistency Index , CI

Question 44

For soils with a particular mineralogy, the plasticity index is linearly related to the amount of the clay fraction. This is called ______________

Answer 44

Activity, A= PI/ Clay fraction (%)

Question 45

_____________ is one of the factors used in identifying expansive or swelling soils.

Answer 45

Activity, A

Question 46

Classification of Clay based on Activity (A):

Answer 46

A< 0.70 = Inactive 0.70 < A < 1.20 = Normal A>1.20 = Active

Question 47

It is the Moisture content (in percent) which the volume of the soil mass ceases to change.

Answer 47

Shrinkage Limit, SL

Question 48

Three limits are defined based on the water content that causes a change of state. These are:

Answer 48

a. liquid limit (LL) - the water content that caused the soil to change from a liquid to a plastic state; b. plastic limit (PL)- the water content that caused the soil to change from a plastic to a semisolid; and c. shrinkage limit (SL) - the water content that caused to change from a semisolid to solid.

Question 49

The soil strength is lowest at the liquid state and highest at the solid state. (True or False?)

Answer 49

True