The Application of Geosynthetics in Civil Engineering 1442024

Abstract

Geosynthetics types,functions ,and applications

Full text

The Application of
Geosynthetics in Civil
Engineering
ASSOCIATE-PROFESS OR AT CIVIL ENGINEERING DEPARTMENT AT OMAR
ALMUKHTAR UNIVERSITY, ELBIDA,LIBYA
Dr. Enas Abdalnabi omar

What are Geosynthetics?
•Geo = earth
•Synthetic = human made
•Geosynthetics = human made materials (polymers) used with soil,
rock, earth or other geotechnical materials as an essential part of a
project, structure or system.

Geosynthetic
A geosynthetic is a planar product manufactured from polymeric material
used with soil, rock, earth, or other geotechnical engineering related material
as an integral part of a man-made project, structure, or system.

Polymer - Types & Materials
•Polypropylene(PP): A type of polymer used in geosynthetics
•Polyethylene (HDPE, LDPE, LLDPE): Another type of polymer used in geosynthetics
•Polystyrene (PS): A polymer material commonly used in geosynthetics
•Polyvinyl Chloride (PVC) Polyamide (PA) eg. Nylon Polyester: Types of polymers such as PVC, PA,
Nylon, and Polyester used in geosynthetics
•Acrylonitrile Butadiene Styrene (ABS): Another polymer material utilized in geosynthetics

Types & Functions
Type Separation Reinforcem
ent
Filtration Drainage Containment
Geotextiles X X X X
Geogrid X
Geonet X
Geomembrane X
GCL X
Geofoam X
Geocell X X
Geocomposite X X X X X

Types & Functions
Type Separation Reinforcem
ent
Filtration Drainage Containment
Geotextiles X X X X
Geogrid X
Geonet X
Geomembrane X
GCL X
Geofoam X
Geocell X X
Geocomposite X X X X X

Roles or Functions of Geosynthetics
•Separator
•Reinforcement
•Drainage
•Filter
•Energy absorber
•Container
•Barrier

Types of Geosynthetics
•Geotextiles (GT): Used for soil stabilization and erosion control
•Geogrids (GG): Provide reinforcement for retaining walls and slopes
•Geonets (GN): Used for drainage and filtration in civil engineering projects
•Geomembranes (GM): Impermeable liners for containment applications
•Geosynthetic clay liners (GCL): Provide barrier and containment functions in environmental projects
•Geocomposites (GC): Combination of different geosynthetic materials for multifunctional applications
•Geo others: Includes Geopipe, Geofoam, Geocells, and Geomesh for specialized geotechnical
purposes

Geotextiles (GT)
Geotextiles, often abbreviated as GT, are a type of geosynthetic material
used in civil engineering projects. They are designed to provide separation,
filtration, drainage, and reinforcement in various applications.

Geotextiles
These are permeable fabrics made from synthetic fibers and are
commonly used for filtration, separation, and reinforcement in various civil
engineering applications. They prevent soil erosion, provide drainage, and
enhance the s tability of slopes and embankments.

Geotextiles
Woven
Used for separation, reinforcement and
drainage. Used with pavement, roads,
railroads, structures , and rip rap.
Strength is support, stabilization, and
drainage to prevent erosion and or
collapsing of the ground around a road,
railroad, etc.
Nonwoven
Used for separation, reinforcement,
and filtration. Used with drains,
geomembranes, aggregate.
Reclamation mainly uses as a cushion
to protect geomembranes from being
punctured by aggregate, the subgrade,
etc.

Geomembranes (GM)
1Function: contain liquids or gases
Reclamation uses geomembranes in canals, ponds, reservoirs, dam faces,
and roof tops to prevent water from seeping into unwanted areas.
2The primary makeup of most Geomembranes is any of the
following polymers.
HDPE, LLDPE, PP, PVC, CSPE, or EPDM
3Additives are used to improve properties required for
durability, UV exposure, etc.
Carbon Black is a pigment that is used for UV stabilization. Plasticizers impart
flexibility to prevent punctures and tears. Biocides to kill organic material

Geonets(GN)
Highly permeable materials resembling plastic mesh used for drainage
and filtration applications.
Geonets enhance water flow within soil structures, reducing hydrostatic
pressure and preventing saturation-induced failures in retaining walls,
landfills, and drainage systems.

Geonets are grid like materials consisting of parallel sets of ribs
overlaying other parallel sets of ribs at various angles. They are
often sandwiched between GT’s.
The function of a geonet is to laterally drain liquids or gases within
the plane of the material.
Example –used under sports fields or putting greens to prevent
sitting water.
Two main types of geonets used.
Triplanar
- these types are used whenever drainage is required
under high loads.
Biplanar
–these types of geonets are
used to transport large fluid or gas flows under very minimal loads
such as leak detection layers in ponds.
Geonets(GN)

Geocell
detention pond to protect the underlying geomembrane liner from UV degradation
and mechanical damage.
Geocells are a three-dimensional structure much like a honeycomb that is
meant to be filled with aggregate, soil, etc. (See images to the right)
Function
Separation, Reinforcement or Both
Reclamation has used these to retain a coble/gravel mixture on the side slope of
a Primary Use
Reclamation : canals and ponds
Soil stabilization, erosion control, and structural reinforcement for load support.

geocell
•they create a stable foundation for roads, railways, and load-bearing structures .
•Geocells reduce soil erosion,
•increase load-bearing capacity, and
•enhance vegetation growth in erosion control applications .

Geocells Earth Retention
Geocells are a three-dimensional structure much like a honeycomb that is
meant to be filled with aggregate, soil, etc. (See images to the right)
Geocells are available in different colors to match the surroundings.

Geocells Slope
Stabilization
Geocells are a three-dimensional structure much like a honeycomb that is meant
to be filled with aggregate, soil, etc. (See images to the right)
Note geocell pattern in compacted gravel fill material. Outer cells are filled
with soil to allow planting of vegetation and provide a “green” appearance in
the future.

Geosynthetic Clay Liners (GCL)
•Geosynthetic Clay Liners (GCL’s) are hydraulic barriers that generally
consist of bentonite clay sandwiched between two geotextiles or
geomembranes.
•GCL’s are primarily used in landfill applications in place of compacted clay (CC) liners or
geomembranes.
•Fast + Easy to Install
•Very low conductivity, swell to 1 5 times size when hydrated.
•Self healing up to 70 mm holes.
•Low cost when CC is not available.
•Maximize capacity compared to CC
•Reclamation has used GCL’s in canals and ponds.
•1 2 in min. soil cover to provide seal
•Soil cover sloughs from side slopes
•Cover significantly reduces capacity

Geogrids (GG)
Geogrids are materials with open spaces formed by intersecting ribs or
other configurations. They are primarily used for soil reinforcement in
retaining walls, road construction, and steep slope stabilization. Geogrids
distribute loads over a wider area, reducing soil settlement and increasing
bearing capacity.

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Geogrids/Geofoam
Geogrids are used to reinforce soils or other materials.
Retaining walls
Side slopes
Reinforce soils or other base materials below roads or other structures.
Geofoam is large blocks of expanded polystyrene (EPS).
Slope stabilizer
Retaining wall backfill
Road embankments
Pavement insulation

Geogrids EWP - Reinforced Fill
Road
Geogrids are used to reinforce soils or
other materials.
Bi-axial Geogrid
Retaining walls
1/4” Rebar
Reinforce soils or other base materials below roads or other structures. Uni-axial
Geogrid

Geogrids EWP - Reinforced
Fill
•Used for reinforcing fill materials in construction projects
•Provides stability and strength to the fill
•Improves the load-bearing capacity of the soil

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Geogrids EWP –MSE Wall
Geogrids are used to reinforce soils or other materials.
Retaining walls
Side slopes
Reinforce soils or other base materials below roads or other structures.

Geofoam (GF)

Geofoam: Lightweight,
expanded polystyrene (EPS)
or polyurethane foam blocks
used as lightweight fill
material in construction
projects.
Geofoam: Lightweight, expanded polystyrene (EPS) or polyurethane foam
blocks used as lightweight fill material in construction projects.
Geofoam reduces loads on underlying soil, minimizes settlement, and
provides thermal insulation.
It is commonly used in road embankments, bridge approaches, and slope
stabilization.

Geocomposites (GC)
Geocomposites (GC) are used for various applications in construction
and engineering projects. They offer a versatile solution for combining
different geosynthetic materials to achieve specific performance goals.
Composite materials combining two or more geosynthetic components,
such as geotextiles, geogrids, or geomembranes. Geocomposites offer
multifunctionality, serving purposes like drainage, filtration, separation,
and reinforcement simultaneously. They are commonly used in landfill
drainage systems, erosion control, and road construction.

Geocomposite
–a combination of any of the previous discussed
geosynthetic materials.
The goal of a geocomposite is to combine the best properties of the
different types of materials to find an optimal low-cost solution to a specific
problem.
Geocomposite can provide separation, reinforcement, filtration, drainage,
and containment.
Geocomposite Examples
Geotextile-Geonet Geocomposite
Geotextile-Geomembrane Geocomposite
Geomembrane-Geogrid Geocomposite
Geotextile-Geogrid Geocomposite
Geocomposite for erosion control
These specialized geosynthetics combine erosion control mats, blankets, or
turf reinforcement mats with geotextiles to provide stabilization on slopes,
channels, and shorelines. They promote vegetation growth, reduce surface
erosion, and prevent soil loss, contributing to sustainable land management
practices.

•its really buried plastic pipe!
•function is always drainage
•HDPE and PVC most common
•can be smooth walled or corrugated corrugated
HDPE growth is enormous
Geopipe (GP)
Large, tubular containers made from high-strength geotextiles filled
with sediment or slurry.
Geotubes are employed for dewatering, shoreline protection, and
coastal restoration projects.
They efficiently separate solids from liquids, facilitate sediment
consolidation, and create stable containment structures
Geotubes:

Properties of Geosynthetics -
Parameters
Physical
Chemical
Mechanical
Hydraulic
Endurance
Degradation

Physical
Thickness
Specific Gravity
Mass per unit area
Porosity
Percent open area
Apparent opening size
Parameters . . . .

Chemical
Polymer type
Filler material
Carbon black percentage
Plasticizers and additives
Manufacturing process
Parameters . . . .

Mechanical
Tensile strength
Compressibility
Elongation
Tear/impact/puncture resistance
Burst strength
Seam strength
Fatigue resistance
Interface friction with soil
Anchorage in soil
Parameters . . . .

Hydraulic
Permittivity (cross plane permeability)
Transmissivity (in plane permeability)
Clogging potential
Parameters . . . .

Endurance
Installation damage potential
Tear/impact/puncture resistance
Abrasion resistance
creep
Parameters . . . .

Degradation
Resistance against
Ultraviolet radiation
Temperature
Oxidation
Aging
Chemical and Biological reactions
Parameters . . . .

Geosynthetics
Geotextiles
Geotextiles are permeable fabrics used in the
construction of roads, embankments, and other
civil engineering projects to improve soil stability
and drainage.
Geogrids
Geogrids are materials used to reinforce soil,
providing strength and stability to structures
such as retaining walls, slopes, and pavements.
Geomembranes
Geomembranes are impermeable liners used
for containment applications, such as waste
management facilities, reservoirs, and mining
operations.
Geosynthetic Clay Liners
Geosynthetic Clay Liners are composite liners
used for environmental containment, such as
landfills and impoundments, to prevent the
migration of contaminants into the surrounding
environment.

Geosynthetics in water
management
Geosynthetics in Landfills
Geosynthetics in slope stabilization
Geosynthetics in Sandy and Muddy
Coastal Management

NRCS Applications
•Geotextiles
•Geomembranes
•Geosynthetic Clay Liners
•Geogrids
•Geocells
•Geocomposites
Geosynthetics in the Drainage system
Geosynthetics in Roadways

Properties of Geosynthetics Range of Values
Type
Thickness
(mm)
Mass per
unit area
(gsm)
Tensile
strength
(kN/m)
Elongation
(%)
Apparent
opening size
(mm)
Non-Woven
Geotextile 0.25 –7.5 100 –2000 5–100 20 –100 0.02 –0.6
Woven
Geotextile 0.25 –3.0 100 –1500 20 –400 10 –50 0.05 –2.0
Geomebranes 0.25 –3.0 250 –3000 10 –50 50 –200 ~ 0
Geogrids 5.0 –15.0 200 –1500 10 –200 5–25 10 –100
Geonets 3.0 –10.0 100 –1000 – – 5–15

Separation
High tensile strength 20 –400 kN/m
Allow flow of water but no mixing of soil
High burst strength
High tear/impact/puncture resistance
(Geotextiles (usually woven
Functional requirements

Filtration
Cross-plane permeability higher than base soil
(10e-5 to 1 m/s)
Pore size small enough to enable retention of
fines (95% pore size –0.02 to 2.0 mm)
Low clogging potential
Geotextiles (usually non-woven)
Functional requirements . . . .

Drainage
Requirements of filtration
High in-plane permeability
Geotextiles (thick non-woven) Geonets
sandwiched b/w geotextiles
(Geocomposite sheet drain)
Functional requirements . . . .

Reinforcement
High tensile strength
Low elongation (high stiffness) (5 to 25%)
High shearing resistance along soil
reinforcement interface
Geotextiles (low elongation)
Geogrids
Functional requirements . . . .

Barrier
High imperviousness (10e-12 to 10e-15 m/s)
Leakproof welding along seams
No slippage when laid along sloping ground
•Geomebranes
Functional requirements . . . .

NRCS Applications
Geotextiles
Geotextiles are used
for various
applications in civil
engineering and
construction. They
provide
reinforcement,
filtration, and erosion
control in different
projects.
Geomembranes
Geomembranes are
impermeable liners
used in containment
systems for waste
management, water
storage, and other
environmental
protection
applications.
Geosynthetic
Clay Liners
Geosynthetic clay
liners are composite
liners used for
environmental
containment
applications, such as
landfills, mining, and
pond liners.
Geogrids
Geogrids are used to
reinforce soils or other
materials in retaining
walls, side slopes,
and base materials
below roads or other
structures.

NR CS Applications
Geotextiles
Geotextiles are used
for various
applications in civil
engineering, including
soil stabilization,
erosion control, and
drainage
management.
Geomembranes
Geomembranes
provide a reliable
barrier for
containment
applications, such as
waste management
facilities, ponds, and
reservoirs.
Geosynthetic
Clay Liners
Geosynthetic Clay
Liners (GCL’s) are
hydraulic barriers
used in landfill
applications and
canals, offering low
conductivity and self-
healing properties.
Geogrids and
Geofoam
Geogrids and
Geofoam are
essential for soil
reinforcement in
retaining walls, road
construction, and
steep slope
stabilization,
distributing loads and
increasing bearing
capacity.

NRCS Applications
Geotextiles
Geotextiles are permeable fabrics used in the
construction of roads, embankments, and
other civil engineering projects. They provide
filtration, separation, and reinforcement,
contributing to the overall stability and
longevity of the structure.
Geomembranes
Geomembranes are impermeable
membranes used in containment applications
such as landfills, ponds, and reservoirs. They
provide a barrier to prevent the seepage of
liquids and gases, protecting the environment
and underlying structures.
Geosynthetic Clay Liners
Geosynthetic Clay Liners (GCL’s) are
hydraulic barriers that generally consist of
bentonite clay sandwiched between two
geotextiles or geomembranes. They are
primarily used in landfill applications in place
of compacted clay (CC) liners or
geomembranes.
Geogrids
Geogrids are materials with open spaces
formed by intersecting ribs or other
configurations. They are primarily used for
soil reinforcement in retaining walls, road
construction, and steep slope stabilization.
Geogrids distribute loads over a wider area,
reducing soil settlement and increasing
bearing capacity.

NRCS Applications
Geotextiles
These are
permeable fabrics
made from synthetic
fibers and are
commonly used for
filtration, separation,
and reinforcement in
various civil
engineering
applications. They
prevent soil erosion,
provide drainage,
and enhance the
stability of slopes
and embankments.
Geomembranes
Function: contain
liquids or gases.
Reclamation uses
geomembranes in
canals, ponds,
reservoirs, dam
faces, and roof tops
to prevent water
from seeping into
unwanted areas.
Geosynthetic
Clay Liners
Used for separation,
reinforcement, and
filtration. Used with
drains,
geomembranes,
aggregate.
Reclamation mainly
uses as a cushion to
protect
geomembranes
from being
punctured by
aggregate, the
subgrade, etc.
Geogrids
Strength is support,
stabilization, and
drainage to prevent
erosion and or
collapsing of the
ground around a
road, railroad, etc.

B enefits of us ing geos ynthetics
1Cos t-Effective
Geosynthetics reduce construction costs by extending the service life of
infrastructure and minimizing the need for maintenance.
2Environmental Sus tainability
They contribute to environmental protection by preventing soil erosion,
promoting vegetation growth, and improving water quality.
3Enhanced Performance
Geosynthetics enhance the structural integrity of soil, providing stability and
reinforcement for a wide range of applications.