Terms I Flashcards
1
Q
The earth pressure exerted on the wall which causes the
wall to move away from the soil. The earth surface will tend
to be lowered, and lateral pressure on the wall will be
decreased. If the wall moves far enough away, shear failure
of the soil will occur, and a sliding soil wedge will tend to
move forward and downward.
A
Active earth pressure
2
Q
The ratio of the plasticity index to the percentage of clay-
size fraction by weight.
A
Activity
3
Q
The Swedish soil scientist who developed a series of tests to
evaluate the relationship between moisture content and soil
consistency.
A
Albert Atterberg
4
Q
Refers to the loading per unit area that the soil is able to
support without unsafe movement.
A
Allowable bearing capacity
5
Q
It is the working pressure that would ensure a margin of
safety against collapse of the structure from shear failure.
A
Allowable bearing capacity bearing capacity or Safe bearing
capacity
6
Q
Developed a new engineering soil classification system
known as Unified Soil Classification System (USCS).
A
Arthur Casagrande
7
Q
This defined the boundaries of four states in terms of limits
as follows, liquid limit, the boundary between the liquid and
plastic states, plastic limit, the boundary between the plastic
and semi-solid state and ® shrinkage limit, the boundary
between the semi-solid and solid states.
A
Atterberg Limits
8
Q
Refers to the ability of a soil to supports hold up a
foundation and structure.
A
Bearing capacity
9
Q
This is the capacity factor in Terzaghi’s bearing capacity
formula which cites the influence of the soil’s cohesion on
its bearing capacity
A
Bearing capacity factor Nc
10
Q
This is the capacity factor in Terzaghi’s bearing capacity
formula which cites the influence of surcharge on its bearing
capacity
A
Bearing capacity factor Nq
11
Q
This is the capacity factor in Terzaghi’s bearing capacity
formula which cites the influence of soil weight and
foundation width or radius.
A
Bearing capacity factor Ny
12
Q
The rise of water in a small diameter tube inserted into the
water the rise being caused by both cohesion of the water
molecules (surface tension) and adhesion of the water to
the tubes wall.
A
Capillary
13
Q
He developed an apparatus for the liquid limit test that
consists of a semi spherical brass cup that is repeatedly
dropped onto a hard rubber base from a height of 10 mm by
a cam-operated mechanism.
A
Casagrande
14
Q
French scientist who used the principles of calculus for
maxima-minima to determine the true position of the sliding
surface in soil behind a retaining wall.
A
Charles Coulomb
15
Q
It is the tests necessary to determine index properties”
A
Classification test
16
Q
A type of soil where the fine fractions of the soil have a
plasticity index of 11 or more.
A
Clayey
17
Q
It consists of gravel and sand where the individual particles
are large enough to be distinguished without magnification.
A
Coarse Grained Soil
18
Q
The ratio of the horizontal to vertical effective stresses.
A
Coefficient of lateral earth pressure
19
Q
Another term for coefficient of gradation
A
Coefficient of curvature or Coefficient of concavity
20
Q
The ratio of lateral stress to the vertical stress.
A
Coefficient of earth pressure
21
Q
The ratio of the square of the diameter corresponding to
30% finer to the product of the effective size and diameter
corresponding to 60% finer.
A
Coefficient of gradation
22
Q
Is a proportionality constant determine the flow velocity of
water through soils.
A
Coefficient of permeability
23
Q
The ratio of the effective active pressure on the vertical
plane to the vertical effective overburden pressure.
A
Coefficient of Rankine’s active pressure
24
Q
The ratio of the effective passive pressure on the vertical
plane to the vertical effective overburden pressure.
A
Coefficient of Rankines passive pressure
25
Shear strength of a soil when tested with no lateral load
applied to the specimen.
Cohesion
26
Soil deposits that experience significant decrease in volume
when exposed to water.
Collapsible soils
27
Soils formed by movement of soil from its original place
during landslides. by gravity such as during landslide.
Colluvial soils
28
Is defined as the process by which the soil particles are
artificially rearranged and packed together into a state of
closer contact by mechanical means in order to decrease its
porosity and thereby increase its dry density.
Compaction
29
The densification of soil by removal of air, which requires
mechanical energy.
Compaction
30
It is the slope of the field consolidation line. It is an index
used for calculation of field settlement caused by
consolidation of soil.
Compression index
31
Refers to the texture and firmness of a soil and is often
directly related to the strength.
Consistency
32
Is defined as the ratio of the difference between liquid limit
and the natural water content to the plasticity index of a
soil.
Consistency index
33
A tri-axial test similar to the consolidated undrained test
except that the specimen is allowed to drain as the axial
load is applied so that high excess pore pressures do not
develop. Because the permeability of clayey soils is low, the
axial load must be added very slowly during consolidated
drained test so that excess pore pressure can be dissipated.
Consolidated drained tes
34
A tri-axial test which is performed by placing the specimen
in the chamber and introducing lateral pressure. The sample
is then allowed to consolidate under the lateral pressure by
leaving the drain lines open. The drain lines are then closed
and axial stress is increased without allowing further
drainage.
Consolidated undrained test
35
A time dependent settlement of soils resulting from the
expulsion of water from the soil pores. Any volume decrease
of a soil mass.
Constant head tes
Consolidation
36
Two standard laboratory tests used to determine the
hydraulic conductivity of soil
Constant head test and the falling head test
37
The pressure acting between a footings base and the soil
below.
Contact pressure
38
A stress state reached in a soil when continuous shearing
occurs at constant shear stress and constant volume.
Critical state
39
The void ratio that exists prion to a shearing process in
which the net volume change at failure is zero.
Critical void ratio
40
Another term for tri-axial test.
Cylindrical compression test
41
Average particle diameter of soil.
D50
42
The constant of proportionality, factor that indicates if the
volume of flow is to be great or small, relates to the ease or
difficulty with which the water moves through the soil.
Darcy's coefficient of permeability
43
The quantity of water flowing through the soil in a given
period was proportional to the soil area normal to the
direction of flow and the difference in water levels indicated
in the piezometers, and inversely proportional to the length
of soil between piezometers through which flow took place.
Darcy's Law
44
Foundation that have a depth of embedment to width ratio
is greater than four (4).
Deep foundation
45
The ratio of the volume of water to the volume of voids.
Degree of saturation
46
The ratio of the unconfined compression strength in an
undisturbed state to that in a remolded state.
Degree of sensitivity
47
A test (also known as water mobility on shaking test)
consists of placing a part of moist soil in the palm of the
hand and then shaking the hand. If a shiny, moist surface
appears on the soil after shaking it in the open hand and
then becomes dull and dry when the pat is squeezed by
closing the hand a non plastic soil (silt) is indicated.
Dilatancy test
48
A measure of the change in volume of soil when it is
distorted by shearing.
Dilation
49
A shear test where in the shear box that contains the soil
specimen is generally kept inside a container that can be
filled with water to saturate the specimen.
Direct shear test
50
The longest vertical path that a water particle will take to
the drainage surface.
Drainage path
51
A shear test made on saturated soil specimen by keeping
the rate of loading slowly enough so that the excess pore
water pressure generated in the soil is completely dissipated
by drainage.
Drain direct shear test
52
The weight per unit excluding water volume of soil,
excluding water.
Dry unit weight
53
A technique used for the densification of granular soil
deposits which consists primarily of dropping a heavy weight
repeatedly on the ground at regular intervals.
Dynamic compaction
54
Refers to lateral pressure caused by earth that is prevented
from lateral movement by an unyielding wall.
Earth pressure at rest
55
Is a measure of the shear strength of soil.
Effective friction angle
56
The average particle diameter of the soil at 10 percentile,
that is 10% of the particles are smaller than this size.
Effective particle size (D10)
57
A parameter of a soil which indicates the diameter in the
particle size distribution curve corresponding to 10% finer.
Effective size
58
The weight of soil solids in a submerged soil per unit
volume.
Effective unit weight
59
It is the depth below the ground surface where the base of
the foundation rests.
Embedment depth
60
It is one that transfers almost all the structural load to the
soil at the bottom end of the pile.
End bearing or Point bearing pile
61
A pile that is driven until it rests on a hard, impenetrable
layer of soil or rock, the load of the structure is transmitted
primarily axially through the pile to the impenetrable layer.
End-bearing pile
62
It is a line representing constant head.
Equipotential line
63
It is the ratio of the ultimate net bearing capacity to the
allowable bearing capacity or to the applied maximum
vertical stress.
Factor of safety or Safety factor
64
Types of soil which have at least 50% passing the #200 sieve.
Fine grained soils
65
Index is measured as the slope of flow curve.
Flow index
66
It is the flow path of a particle of water.
Flow line
67
It is a graphical representation of o flow field.
Flow net
68
It is a foundation consisting of a small slab for transmitting
the structural load to the underlying soil.
Footing
69
It is a structure that transmits loads to the underlying soils.
Foundation
70
A pile carrying the load of structure primarily by skin friction
or adhesion between the surface of the pile and adjacent
soil.
Friction pile
71
The vertical expansion of soil caused by freezing water
which cause the soil mass to move upward.
Frost heave
72
When the temperature in a soil mass drops below water's
freezing point, water in the voids freezes and therefore
expands, causing the soil mass to move upward. The
freezing water within causes vertical expansion of soil
Frost heave
73
The shear produce by dense sand and stiff clay.
General shear
74
The subdiscipline of civil engineering that involves natural
materials found close to the surface of the earth which
includes the application of the principles of soil mechanics,
and rock materials to the design of foundations, retaining
structures and earth structures.
Geotechnical engineering
75
Water under gravity in excess of that required to fill the soil
pores.
Groundwater
76
To evaluate the quality of soil as a highway sub grade
material, one must also incorporate a number which is
expressed in terms of the following parameters, the
percentage passing through the no. 200 sieve, the liquid
limit and plasticity index
Group index
77
The measure of how easily water flows through the soil
Hydraulic conductivity
78
Another term for coefficient of permeability
Hydraulic conductivity
79
The study of water movements across the earth.
Hydrology
80
Two laboratory test to measure the grain size distribution of
soil.
Hydrometer analysis and Sieve analysis
81
One of the methods of the mechanical analysis in
determining the size range of particles smaller than 0.075
mm in diameter.
Hydrometer analysis
82
Resulted from the cooling and hardening of molten rock
called magma, which originated deep within the earth.
Igneous rock
83
A type of settlement which is caused by the elastic
deformation of dry soil and of moist and saturated soils
without any change in the moisture content.
Immediate settlement
84
This refers to volumetric weight, usually expressed as kN/m3
or pound per cu.ft.- of a soil in the undisturbed condition or
in a compacted fill.
In place density
85
Those properties that help define a soils engineering
qualities and that are used to assist in determining accurate
classification or properties of soil that indicate the type and
condition of the soil and provide relationship to structural
properties such as strength and compressibility or tendency
for swelling and permeability.
Index properties
86
Refers to the weight or force that acts at the point, or on the
surfaces, where soil particles are in contact.
Inter granular weight
87
Another term for specific permeability.
Intrinsic permeability
88
The moisture content at the point of transition from plastic
to liquid state.
Liquid limit
89
It is a condition that can occur when saturated cohesionless
sand deposits exist in a relatively loose condition. It usually
occur where serious ground settlement can occur in areas
underlain by saturated sand in a loose condition, such
deposits can loose much of their shear strength due to
vibrations or seismic shocks.
Liquefaction
90
Is the ratio of the difference between the natural water
content and the plastic limit to the plasticity index.
Liquidity index
91
The shear produce by loose sand and soft clay.
Local shear
92
Soils formed by deposition in the seas.
Marine soils
93
The max. dry unit weight that a soil can attain in using a
specified means of compaction.
Max. dry unit weight
94
It is the determination of the size range of particles present
in a soil, expressed as, percentage of the total dry weight.
Mechanical analysis
95
A relatively simple means of soil stabilization that is carried
out by adding soil material is usually mechanically mixed
with the natural soil and worked together, after which the
mixture is compacted.
Mechanical stabilization
96
The slope of the curve between two stress points in a plot of
vertical effective stress vertical strain graph.
Modulus of volume compressibility
97
Skin friction that causes down drag.
Negative skin friction
98
A type of soil whose present effective over burden pressure
is the maximum pressure. that the soil was subjected to in
the past.
Normally consolidated soil
99
The moisture content at which the maximum dry unit
weight is attained.
Optimum moisture content
100
The water content required to allow a soil to attain its max.
dry unit weight.
Optimum water content
101
A type of soil whose present effective overburden pressure
is less than that which the soil expected in the past.
Over consolidated soil
102
The ratio of over consolidation pressure to present
overburden pressure.
Over consolidation ratio
103
A soil property which indicates the ease with which water
will flow through the soil.
Permeability
104
The earth pressure exerted on the wall which causes the
wall to move towards the soil. The earth surface will tend to
be raised, and lateral pressure on the wall will be increased.
If the wall moves far enough towards the soil, shear failure
of the soil will occur, and a sliding soil wedge will tend to
move backward and upward.
Passive earth pressure
105
The constant-head permeability apparatus use for testing
the coarse- grained soils, such as sands, where the volume
of flow through the soil will be relatively large.
Permeameter
106
A slender, structural member consisting of steel or concrete
or timber.
Pile
107
The condition where every point in a sill mass is on the
verge of failure.
Plastic equilibrium in soil
108
The moisture content at the point of transition from semi-
solid to plastic state.
Plastic limit
109
The amount of water which must be added to change a soil
from its plastic limit to its liquid limit is an indication of this
of the soil.
Plasticity
110
Is the different between liquid limit and plastic limit.
Plasticity index
111
The pressure in the water within the soil voids.
Pore water pressure
112
The ratio of the volume of voids to the total volume.
Porosity
113
The maximum effective past pressure on the soil.
Pre consolidation pressure
114
Past maximum effective stress of the maximum vertical
effective stress that a soil was subjected to in the past.
Pre consolidation stress
115
The ratio of primary to total compression.
Primary compression ratio
116
The change in volume of a fined-grained soil caused by the
expulsion of water from the voids and the transfer of load
from the excess pore water pressure to the soil particles.
Primary consolidation
117
A type of settlement which is the result of a volume change
in saturated cohesive soils because of expulsion of the
occupies the void spaces.
Primary consolidation settlement
118
The laboratory test generally used to obtain the maximum
dry unit weight of compaction and the optimum moisture
content.
Proctor compaction
119
A device use to measure the specific gravity.
Pycnometer
120
The average slope of the unloading/ reloading curves in a
plot of the logarithm of vertical effective stress versus void
ratio.
Recompression index
121
The in situ void ratio divided by the void ratio when the soil
is in its densest and its loosest condition.
Relative density
122
Three different methods of field density test.
Sand Cone Method, Rubber Balloon Method and Nuclear
Method
123
The weight of saturated soil per unit volume.
Saturated unit weight
124
The change in volume of a fined-grained soil caused by the
adjustment of the soil fabric (internal structure) after
primary consolidation has been completed.
Secondary compression
125
A type of settlement which is observed in saturated
cohesive soils and is the result of the plastic adjustment of
soil fabric.
Secondary consolidation settlement
126
It is the stress (similar to frictional stress in pipes) imposed
on a soil as water flows through it.
Seepage stress
127
Is defined as the ratio of its unconfined compression
strength in the natural or undisturbed state to that in the
remolded state, without any change in the water content.
Sensitivity
128
Foundations that have depth of embedment to width ratio is
less than four.
Shallow foundation
129
It is one in which the ratio of the embedment depth to the
minimum plan dimension which is usually the width, is Df/B≤2.5.
Shallow foundation
130
The max. internal resistance to applied shearing forces.
Shear strength of a soil
131
Net change in volume from the bank to compacted
conditions
Shrinkage factor
132
Is defined as the difference between the plastic and
shrinkage limits of a soil in other words, it is the range of
water content within which a soil is in a semi- solid state of
consistency.
Shrinkage index
133
The moisture content in percent, at which the transition
from solid to semi solid state takes place.
Shrinkage limit
134
Is defined as the ratio of the volume change expressed as
per cent of the dry volume to the corresponding change in
moisture content from the initial value to the shrinkage
limit.
Shrinkage ratio
135
One of the methods of the mechanical analysis in
determining the size range of particles larger than 0.075 mm
in diameter
Sieve analysis
136
A type of soil where the fine fractions of the soil have a
plasticity index of 10 or less.
Sillty
137
It is frictional or adhesive stress on shaft of a pile.
Skin friction stress or shaft friction stress or adhesive stress
138
The branch of science that deals with the study of the
physical properties of soil and behavior of soil masses
subjected to various types of forces.
Soil mechanics
139
is defined as the geometric arrangement of soil particles
with respect t one anothe
Soil structure
140
Materials that are derive from the weathering of rocks.
Soil
141
The application of the principles of soil mechanics to practical problems.
Soils engineering
142
A measure of uniformity and is generally encountered in
geologic works and expressed as: So=√D75/D25
Sorting coefficient
143
Is the ratio of the unit weight of a given material to the unit
weight of water.
Specific gravity
144
A type of test to determine the shear strength properties of
soil and soil bearing capacity which is done by using a 50
mm split spoon sampler which is used in conjunction with a
64 kg drive weight. This test gives the number of blows N to
drive the sampler 0.3 m. into undisturbed soil by using a 64
kg weight falling at a height of 0.76 m.
Standard penetration test
145
It is the behavior of a soil as a viscous fluid when seepage
reduces the effective stress to zero.
Static liquefaction
146
Plasticity index defines the range of water content for which
the soil behaves like a plastic material, but the liquidity index
gives a measure.
Strength
147
A wall footing having length to width ratio is more than 5.
Strip footing
148
The grain size distribution of the back fill material is
important factor that controls the rate of densification and
this rating of backfill is defined by a quantity.
Suitability number
149
Develop the basic principles covering the bearing capacity
theory.
Terzaghi and Peck
150
It is the phenomenon of strength loss - strength gain with no
changes in volume or water content. It is a process of
softening caused by remolding followed by a time-
dependent return to the original harder state.
Thixotropy
151
Ratio of plasticity index to the flow index.
Toughness index
152
It is the maximum pressure that the soil can support.
Ultimate bearing capacity
153
It is the maximum load that a group of piles can sustain
before soil failure occurs.
Ultimate group load capacity
154
It is the maximum load that a pile can sustain before soil
failure occurs.
Ultimate load capacity
155
It is the maximum pressure that the soil can support above
its current overburden pressure.
Ultimate net bearing capacity
156
A tri-axial test carried out by placing the specimen in the
chamber and introducing lateral (confining) pressure
without allowing the specimen to consolidate (drain) under
the lateral pressure. An axial load is then applied without
allowing drainage of the sample. This test can be run quickly
because the specimen is not required to consolidate under
the lateral pressure or drain during application of the axial
load.
Unconsolidated undrained test
157
The shear strength of a soil when sheared at constant
volume.
Undrained shear strength
158
The weight of soil per unit volume.
Unit weight
159
The ratio of the corresponding to 60% diameter finer to the
effective size of the soil
Uniformity coefficient
160
In the construction of highway embankments, earth dams,
loose soils must be compacted to increase their unit weights, and increase the bearing capacity of foundation
constructed over them. Vibroflot devices are also used for
compacting granular soil deposits to a considerable depth.
Vibroflotation
161
The ratio of the volume of voids to the volume of solids.
Void ratio
162
The ratio of the weight of water to the weight of solids in a
given volume of soil.
Water content
