Civil Engineering Orientation Module 4 : Geotechnical Engineering Flashcards
is the technical specialty that deals with soil and rock as supporting materials for structures.
Geotechnical Engineering
It deals with the various foundation types that work between the structure and the ground. In addition, it deals with the stability of soil or rock slopes whose failure may cause loss of human lives or damage to property.
Geotechnical Engineering
is a basic science that is concerned with the study of the history of the Earth, the
rocks of which it is composed and the changes that it has undergone or is undergoing.
Geology
the science of rocks and earth processes
Geology
the application of geologic
fundamentals to engineering
Engineering Geolory
Examples of Engineering Geology
mapping of active seismic faults that are to be avoided when making plans for human habitat development, roadway
construction, or power plant construction.
are formed from rock as it is acted upon by physical, chemical, and biological forces.
Soil
Engineering viewpoint of making soil
soil is any earth material that can be removed with a spade, shovel or bulldozer and is the product of natural weathering
Geological viewpoint of making soil
soil may be considered
as the superficial unconsolidated mantle of disintegrated
and decomposed rock material
Pedological viewpoint of making soil
soil is the weathered transformation product of the outermost layer of the solid crust differentiated into horizons varying in type and amounts of mineral and organic constituents,
usually unconsolidated and of various depths.
serve as parent material for natural soil formation
Rocks
rocks that are solidified from a molten or partly molten siliceous solution.
Igneous Rocks
molten or partly molten siliceous solution
Magma
When magma cools and solidifies in direct contact with the atmosphere
Extrusive cooling
When magma cools and solidifies in the subsurface
Intrusive cooling
formed naturally by consolidated or unconsolidated transported materials.
Sedimentary Rocks
rocks that form as a result of subjecting
igneous or sedimentary rocks to elevated temperatures and pressures.
Metamorphic rocks
the study of the ways in which rocks or sediments are arranged and
deformed on the earth.
Structural Geology
Any rock unit that is
recognizable and mappable in the field
Formation
boundaries between formations
Contacts
two-dimensional
view of rock distribution
Map view
a view of a vertical slice of
the earth
Geological cross section
combination of those two
representations and gives a 3-D view of formations and contacts
Block Diagram
Geological structures regularly encountered in civil engineering work
folds, faults, joints and unconformities
wavy undulations developed in the
rocks of the Earth’s crust due to horizontal compression resulting from gradual cooling of the Earth’s crust,
lateral deflection and intrusion of magma in the upper strata.
Folds
rocks bent around an
imaginary line
Fold Axis
where the continuity of the rock mass breaks.
Fracture
fractures in crustal strata
along which appreciable shear displacement of the adjacent rock blocks have occurred relative to each
other, probably due to tectonic activities.
Faults
fracture along which the shear displacement has taken place
Fault plane
a fracture where little or no movement has taken place.
Joint
Occur in several sets and are approximately parallel within a specific
set.
Discontinuities
a material whose
physical, mechanical property, etc., are not all the same in each direction.
Anisotropic
the surface/ plane of separation
between two series of rock beds/geological formations that belong to two different geologic ages and they
are, in most cases, different in their geologic structure.
Plane of Unconformity or the Unconformity
occurs when there is erosion of a layer or layers of deposited rock followed by the
deposition of new sedimentary rock on top.
Unconformity
happens when the ages of the layers of
rock that are abutting each other are discontinuous
Unconformity
Sedimentary layer deposited over eroded horizontal sedimentary layer
Disconformity
Sedimentary layer deposited over eroded angular(tilted or folded) rock
Angular unconformity
Sedimentary layer deposited over eroded igneous or
metamorphic rock.
Nonconformity
a branch of mechanics that studies the mechanical properties of various types of soil and its strength at different
moisture-content levels
Soil Mechanics
the Father of Modern Soil Mechanics
Karl von Terzaghi
old proverb that should be consulted
stitch in time saves nine
Unit used in phase system
SI units
A material is______ if it contains continuous voids
Permeable
interaction between soils and
percolating water
Seepage
a phenomenon by which the soil on the downstream sides of some hydraulic structures get lifted up due to excess pressure of water.
Piping
The pressure transmitted through grain to grain at the contact points through a soil mass
intergranular or effective pressure
pressure that is responsible for the decrease in the void ratio or increase in the frictional resistance of a soil mass.
Effective pressure
Happens if the pores of a soil mass is filled with water and if a pressure-induced into the pore water tries to separate the grains
pore water pressure or neutral stress
The effect of this pressure is to increase the
volume or decrease the frictional resistance of the soil mass.
pore water pressure or neutral stress
This theory states that constant ratios exist between stresses and strains.
Elastic theory
A portion of the applied stress is transferred to the soil skeleton, which in turn causes a
reduction in the excess pore pressure. This process, involving a gradual compression occurring
simultaneously with a flow of water out of the mass and with a gradual transfer of the applied pressure from
the pore water to the mineral skeleton is called _______
Consolidation
process that involves an increase in the water content due to an increase in the volume of the
voids.
Swelling
One of the most important and the most controversial engineering properties of soil
Shear Strength
strength or ability of the soil to resist sliding along internal surfaces within a mass.
Shear Strength
The field and laboratory
investigations required to obtain the essential information on the subsoil
Soil Exploration or Soil Investigation
one of the most important parts of Foundation Engineering
and at the same time the most neglected part of it.
Soil Exploration or Soil Investigation
2 types of slopes
I. Natural slopes
2. Manmade slopes
Slopes that exist in nature and are formed by natural causes
Natural slopes
term used to designate a constant slope of infinite extent.
Infinite slopes
slopes that are limited in extent
Finite slopes
an extremely important consideration in the design and construction of earth darns.
Slope stability
The important factors that cause instability in a slope and lead to failure
- Gravitational force
- Force due to seepage of water
- Erosion of the surface of slopes due to flowing water
- The sudden lowering of water adjacent to a slope
- Forces due to earthquakes
the removal of a certain weight of soil and may
thus lead to an increased stability as far as mass
movement is concerned.
Erosion
Structures that are built to retain vertical or nearly vertical earth banks or any other material
Retaining walls
walls that resist movement because of their heavy sections
Gravity walls
similar to cantilever walls except that the stem of the walls span horizontally between
vertical brackets known as counterforts.
Counterfort walls
similar to counterfort walls except the brackets or buttress walls are provided on the opposite side of
the backfill.
Buttressed walls
walls that are more flexible than
the other types.
Sheet pile walls
earth materials that constitute relatively the thin outer shell
Crust
materials that are made up of small crystalline
units
Minerals
a naturally occurring inorganic substance composed of one
or more elements with a unique chemical composition, unique arrangement of elements (crystalline
structure) and distinctive physical properties
Mineral
a hard, compact and naturally occurring earth material composed of one or more
minerals and is permanent and durable for engineering applications.
Rock
the subject concerned with the study of the response of rock to an applied
disturbance caused by natural or engineering processes.
Rock Mechanics
the engineering
applications of the basic principles and the information available in the subjects of engineering geology and
rock mechanics in an economic way.
Rock Engineering
a large extent of rock, from several metres to few kilometres,
which can include many discontinuities of different forms.
Rock Mass
the steepest inclination of the plane to
horizontal.
Dip or True Dip
the inclination of any arbitrary line on the plane to horizontal, which is always
less than the true dip
Apparent Dip
the trace (or intersection) of the dipping plane with the horizontal reference
plane. It is also the orientation of the horizontal line drawn on the dipping plane. It is perpendicular to the
dip direction.
Strike
the interface between a superstructure and its supporting soil
Foundation
the study of different types of foundation and their proper applications.
It is the application and practice of the fundamental principles of soil mechanics and rock mechanics (i.e.,
geotechnical engineering) in the design of foundations of various structures
Foundation Engineering
types of
foundations:
- Cantilever footings
- Combined footings
- Mat foundations
normally
comprises two footings connected by a beam called a strap.
A strap footing a special case of a combined footing
Cantilever Footing
is a long footing
supporting two or more columns in one row
Combined footing
large
footing usually supporting several columns in two or more
rows
Mat or Raft Foundatios
is the direction of the horizontal line (projection) of the line of dip, measured clockwise from the north which can be in the range of 0° to 360°.
Dip Azimuth
the maximum bearing capacity of soil at which the soil fails by shear
Ultimate Bearing Capacity
a pressure that is safe from shear failure criteria.
Allowable Bearing Pressure
a pressure that is safe from settlement criteria
Safe Bearing Pressure
piles that are used when the horizontal load per pile exceeds the value suitable for vertical piles; used in combination with vertical piles.
Batter Piles or Inclined Piles or Raker Piles
if the lateral load acts on the pile in the direction of batter.
In-Batter Piles or Negative Batter Piles
if the lateral load acts in the direction opposite to that of the batter.
Out-Batter Piles or Positive Batter Piles
installed by excavating; belong to the same category as piles.
Piers
a pile, cast-in-sity, with a diameter less than 0.75m (2.5 ft).
Small Diameter Pile
a pile with a diameter greater than 0.75m (2.5 ft); also called a drilled piers, drilled shafts, and drilled caissons in the USA.
Large Diameter Bored Cast-In-Situ Pile
piers which develop their support from end-bearing on strong soil, “hardpan” or rock; the overlying soil is assumed to contribute nothing to the support of the load imposed on the pier.
Straight-Shaft End Bearing Piers
piers which pass through overburden soils that are assumed to carry none of the load and penetrate far enough into an assigned bearing stratum to develop design and load capacity by side wall friction between the pier and bearing stratum.
Straight-Shaft Side Wall Friction Piers
piers with combined side wall friction and end bearing assigned a role in carrying the design load.
Combination of Straight Shaft Side Wall Friction and End Bearing Piers
frequently termed soil stabilization; in its broadest sense, an alteration of any property of a soil to improve its engineering performance.
Soil Improvement
