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1. OUTLINE
 Introduction
 Properties of Geosynthetics
• Physical properties
• Mechanical properties
• Hydraulic properties
• Endurance properties
 Tensile strength of Geosynthetics
 Function of Geosynthetics
 Application of Geosynthetics

2. GEOSYNTHETICS
 A plannar product manufacture from polymetric
material used with rock ,soil, earth or other
geotechnical engineering related materials an
integral part of man-made project, structure or
systems.
 Families of Geosynthetics are
Geogrid,Geomembrance,Geotextile,Geopipe,
Geonet etc

3. PROPERTIES OF GEOSYNTHETICS
 Physical Properties
 Mechanical Properties
 Hydraulic Properties
 Endurance Properties

4. PHYSICAL PROPERTIES
 Mass per unit area (Weight)
 Thickness
 Specific gravity
 Stiffness

5. MASS PER UNIT AREA
 Five test specimens are to be weighed in a
weighing machine (accuracy of 0.01 g) and average
value is recorded.
 Test samples are of size 100 mm X100 mm
 Unit is expressed as g/m2
 The cost of geotextile is directly related to the
weight of geotextile.

7. THICKNESS
 Geotextiles exhibit different thickness according to
different pressures.
 The thickness is measured to an accuracy of 0.02
mm under a specified pressure of 2.0 kPa.
 Sample size is 200 mm X 200 mm. The thickness is
generally in the range of 0.25 to 8.5 mm.
 The thickness of geogrids and geomembranes are
measured under a normal stress of 20 kPa.

9. SPECIFIC GRAVITY
 Specific gravity can be defined as ratio of the unit
weight of material to the unit weight of distilled
water at 4°C.
 Specific gravity of different geosynthetic materials

10. STIFFNESS OR FLEXURAL RIGIDITY OR
FLEXURAL STIFFNESS
 The geotextile specimen is a 25 mm wide strip.
 The geotextile is placed along the length of a
horizontal plane and bends gravitationally under its
own weight on a inclined plane making an angle of
41.5 degree with the horizontal.

12. STIFFNESS
 Stiffness of the geotextile = (l/2)3 x W
l = length of overhang geotextile and bending
length = l/2 (cm), w = mass per unit area (mg/cm2)
 The unit of stiffness is mg-cm.
 The minimum stiffness of geotextile depends on the
various degree of required workability
 The property is important in field workability
requirements for installation of geotextile.
 If the soil is very poor or California bearing ratio
value is very less, the stiffness of geotextile
required is very high

13. MECHANICAL PROPERTIES
 Compressibility
 Tensile strength

14. COMPRESSIBILITY
 Compressibility indicates the reduction in thickness
under applied pressure. Compressibility of geotextile
depends on its thickness and mass per unit area.
 As the pressure increases, thickness of non-woven
needlepunched (NW-NP) and resin bonded geotextiles
gets reduced significantly and accordingly, the
transmissivity gets reduced.
 Compressibility of woven and non-woven heat bonded
geotextile (NW-HB) is low.
 Compressibility of nonwoven needle-punched geotextile
plays a very important role as most of the time we use
these type of geotextiles to pass the liquid along their
plane.

15. IT IS CLEARLY OBSERVED THAT NONWOVEN NEEDLE
PUNCHED GEOSYNTHETICS ARE MORE
COMPRESSIBLE

16. TENSILE STRENGTH
 Wide width tensile strength
 Very wide width tensile strength test
 Narrow strip tensile strength
 Sewn seam strength of geotextile
 Grab tensile strength
 Trapezoidal tear strength test
 For design purpose, the very wide width tensile test
is not recommended

17. FUNCTIONS OF GEOSYNTHETIC
 Separation - in which a geosynthetic placed between two dissimilar
geotechnical materials, prevents intermixing.
 Filtration - in which a geotextile allows passage of fluids from a soil
while simultaneously preventing the uncontrolled passage of soil
particles.
 Drainage - in which a geosynthetic may collect and transport fluids in its
own plane.
 Reinforcement - in which by virtue of the tensile characteristics, a
geosynthetic resists stresses and contains deformations in geotechnical
structures.
 Barrier - in which a geosynthetic acts as a barrier to liquid/gas.
 In addition, geotextiles serves the following functions:
Protection or cushioning - in which a geotextile serves as a localized
stress reduction layer to prevent or reduce damage to a given surface or
layer.
Surficial erosion control - in which a geotextile may prevent the surface
erosion of soil particles due to surface water run-off and/or wind forces.

18. APPLICATIONS OF GEOSYNTHETICS
 Geosynthetics applications for railroads
 Geosynthetics to deal reflection cracking in pavements
 Geosynthetics applications for hydraulic structures
 Geosynthetics to mitigate coastal and riverbank erosion
 Geosynthetics applications for food and agriculture
 Geosynthetics applications in mining engineering
 Geosynthetics applications in tsunami
 Geosynthetics applications for waste water treatment
Geosynthetic for landfills
 Geosynthetics applications as noise barrier
 To combat or mitigate the acts of terrorism and/or
natural disasters

19. MAIN STRONG REASONS FOR USING IN CIVIL
ENGINEERING ARE AS FOLLOWS:
 Excellent stress-strain behavior
 Good flexibility
 Excellent filtration characteristics
 High water permeability
 Excellent mechanical properties
 Can be welded together
 Does not form by-products
 High resistance to climate condition
 High resistance to chemical and biological attack
 Chemically ultraviolet stabilized
 Time, cost, rapid construction, environment friendly,
sustainability and durability

20. THANK YOU