TRAINING WORKSHOP ON NON-WOVENS IN GEOTEXTILES AT SURAT

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TRAINING WORKSHOP ON NON-WOVENS IN GEOTEXTILES
AT SURAT
5TH MARCH 2008
BY S.K. PURI CHIEF GENERAL MANAGER - NHAI
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National Highways

• Total Length of NHs 65,569 km (2 of total road
  length)
• Roads carry 85 of Passenger and 70 of Freight
  Traffic
• NHs carry about 40 of traffic
• NHAI is entrusted with implementation of National
  Highways Development Project (NHDP)

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Components of NHDP
Phase Length (Km) Cost (Rs crore) Focus
I Bal. 1738 Bal. 9071 Golden quadrilateral (GQ)- connecting Delhi-Mumbai-Chennai- Kolkata-Delhi Total Length 5846
II Bal. 6736 Bal. 43623 North South East west Corridors (NS-EW) Total Length 7300
III 12,109 80,626 State capital connectivity,High traffic density, Imp.centers of tourism economic activity
IV 20,000 27,800 Widening Strengthening to 2-lane with Paved shoulders
V 6,500 41,210 Six laning of high density corridors
VI 1000 Km 16,680 Expressway for connecting important places
VII (Being identified) 16,680 Ring roads to cities, flyovers, by-passes
SARDP-NE 588 5208 Special Accelerated Road Development Programme for NE
ICTT Cochin 17 557 International Container Transhipment Terminal
Total 48,688 2,41,454
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• Definition, Type, Process and Properties

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What is a Geotextile?
Any permeable textile natural or synthetic, used
with foundation soil, rock, earth, or any other
geotechnical engineering related material.
Types of Geotextile
Non-woven
Woven
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Nonwoven Geotextiles
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Nonwoven Geotextiles
Needle Punched nonwoven
Thermally bonded nonwoven
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Woven Geotextiles
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Woven Geotextiles
Slit film tape-on-slit film tape
Extruded tape-on-extruded tape
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Woven Geotextiles
PET multifilament woven fabric
Monofil woven fabric
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Knitted Geotextiles
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Knitted Geotextiles
Knitted base
Upper surface
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Physical Properties
Property Value range
Specific gravity 0.9 1.7
Mass per unit area 135 1000 g/m3
Thickness 0.25 7.5 mm
Stiffness Nil 25,000 mg-cm
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Mechanical Properties
Property Value Range
Compressibility Nil to high
Tensile strength (grab) 0.45-4.5 kN
Tensile strength ( wide width) 9-180 kN/m
Confined tensile strength 18-180 kN/m
Seam strength 50-100 of tensile
Cycle fatigue strength 50-100 of tensile
Burst strength 350-5200 k Pa
Tear strength 90-1300 N
Impact strength 14-200 J
Puncture strength 45-450 N
Friction behavior 60-100 of soil friction
Pullout behavior 50-100 of geotextile strength
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Hydraulic Properties
Property Value Range
Porosity (non wovens) 50-95
Present open area (wovens) Nil to 36
Apparent opening size ( sieve size) 2.0 to 0.075 mm ( 10 to 200)
Permittivity 0.02-2.2s-1
Permittivity under load 0,01-3.0s-1
Transmissivity 0.01 to 2.0 x10-3m2/min
Soil retention turbidity curtains Must be evaluated
Soil retention silt fences Must be evaluated
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Endurance Properties
Property Value Range
Installation damage 0.70 of fabric strength
Creep response g.n.p.if lt40 strength is being used
Confined creep response g.n.p.if lt50 strength is being used
Stress relaxation g.n.p.if lt40 strength is being used
Abrasion 50-100 of geotextile strength
Long-term clogging m.b.e.for critical conditions
Gradient ratio clogging m.b.e. for critical conditions
Hydraulic conductivity ratio 0.4-0.8 appear to be acceptable
g.n.p. generally no problem, m.b.e. must be
evaluated
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Degradation Properties
Property Value Range
Temperature degradation High temperature accelerates degradation
Oxidative degradation m.b.e. for long service lifetimes
Hydrolysis degradation m.b.c. for long service lifetimes
Chemical degradation g.n.p.unless aggressive chemicals
Radioactive degradation g.n.p.
Biological degradation g.n.p.
Sunlight ( UV) degradation Major problem unless protected
Synergistic effects m.b.e.
General aging Actual record to date is excellent
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TYPICAL PHYSICAL PROPERTIES OF GEOTEXTILES
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The polymers used for Geotextile
Abbreviation PE Polyethylene PP
Polypropylene PET Polyester
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Durability Test Methods for Geotextile
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Functions and properties of Geotextiles
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The functions of Geotextiles
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APPLICATIONS FOR GEOTEXTILES

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1 ROADS 1.1 APPLICATIONS IN FILTRATION AND
DRAINAGE
applications
Pavement drains Sub-horizontal drains Curtains Tre
nches Settlement acceleration
materials
Geotextiles Geocomposite drain (PVD)
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1 ROADS 1.2 APPLICATIONS IN EROSION CONTROL
SUPERFICIAL EROSION
silt fences
MATERIALS GEOTEXTILES
Detain carried particles during construction,
before vegetation or under wind effects
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1 ROADS 1.3 APPLICATIONS AS BARRIER
MEMBRANE-ENCAPSULATED SOILS - moisture barrier
maintenance of base material
properties for use in low cost
pavements in wet regions expansive clays good
base soils (lateritic soils,..)
Materials asphalt impregnated geotextiles
reinforced geomembranes geogrids (when hard
cracking)
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1 ROADS 1.4 SEPARATION AND REINFORCEMENT
MATERIALS
SEPARATION GEOTEXTILES GEOCOMPOSITES REINF
ORCEMENT GEOGRIDS GEOTEXTILES
GEOSTRIPS
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2 BENEFITS OF GEOSYNTHETIC SEPARATORS2.1 TYPICAL
APPLICATIONS
Located at the interface between soil and
aggregate

• prevent contamination
• avoid build-up of pore pressure
• avoid loss of granular material

sub-base/sub-grade interfaces
embankments
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2 BENEFITS OF GEOSYNTHETIC SEPARATORS2.2
MECHANISMS
Avoid granular material penetration Puncture
resistance
Filtration Pore size and permeability
Interlock advantages Tensile resistance
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3 BENEFITS OF GEOSYNTHETIC REINFORCEMENT
3.1 PAVEMENT SYSTEMS 3.1.1 ASPHALT OVERLAY
3.1.2 BASE/SUBGRADE 3.2 EMBANKMENTS OVER SOFT
SOILS 3.3 SLOPES AND WALLS
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3.1 PAVEMENT SYSTEMS 3.1.1 ASPHALT
REINFORCEMENT
new roads
Increase in fatigue life Reduction in rutting
maintenance of existing roads
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3.1 PAVEMENT SYSTEMS 3.1.1 ASPHALT
REINFORCEMENT
MECHANISMS
GEOTEXTILE
GEOGRID
WITHOUT REINFORCEMENT
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3.1 PAVEMENT SYSTEMS 3.1.1 ASPHALT
REINFORCEMENT
thin nonwoven geotextiles can be used when
cracking still keeps the aggregates
interlocking (tensile characteristics are not
required)
Note
The asphalt impregnated geotextile do not acts
as a reinforcement, but as a protector layer and
a moisture barrier.
protector layer - retards crack propagation by
deviation moisture barrier increases life time
after cracking
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3.1 PAVEMENT SYSTEMS 3.1.2 SOIL
STABILIZATION
The use of a geosynthetic placed at the
sub-grade/fill interface to increase the support
of construction equipment over a weak or soft
sub-grade
Applications Temporary roadways Initial
construction lift of permanent ways or
embankments Area constructions platforms
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3.1 PAVEMENT SYSTEMS3.1.3 BASE AND SUB-BASE
REINFORCEMENT

• The use of a geosynthetic placed as a tensile
  element at the bottom or
• within a flexible pavement base or sub-base to
• increase the service life
• obtain equivalent performance with a reduced
  structural section
• avoid subsidence problems (sinkholes)

Applications Permanents ways Parking lots Airport
taxiways Container loading facilities Railway
tracks
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3.1 PAVEMENT SYSTEMS 3.1.4 ADVANTAGES
-cost savings in construction and maintenance
-increase of service life -decrease or eliminate
over-excavation and required granular fill in
pavements systems, life cycle cost analysis are
important to show additional maintenance cost
savings
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3.2 EMBANKMENTS OVER SOFT SOIL3.2.1 Applications
-basal reinforcement -piled embankments with
basal reinforcement -reinforcement over areas
prone to subsidence
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3.2 EMBANKMENTS OVER SOFT SOIL3.2.2 Basal
reinforcement mechanisms
rotational stability
bearing capacity
foundation extrusion
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3.2 EMBANKMENTS OVER SOFT SOIL3.2.3 Piled
embankments basal reinforcement design
Ultimate limit states Pile group capacity Pile
group extent Vertical loading shedding Lateral
sliding Overall stability Serviceability
analysis Reinforcement strain Foundation
settlement
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3.2 EMBANKMENTS OVER SOFT SOIL3.2.4 Construction
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3.3 REINFORCED SLOPES AND WALLS3.3.1 applications
landslide reparation bridge abutment increase
working area reduce filled area reduce filling
material
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3.3 REINFORCED SLOPES AND WALLS3.3.2 types
reinforcement spacing
Walls (angle of inclination larger than
80o) Steep slopes Block walls
.
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3.3 REINFORCED SLOPES AND WALLS3.3.2 types
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3.3 REINFORCED SLOPES AND WALLS3.3.3 benefits
Economical solutions Rapid and simple
construction method Allows construction in
difficult terrain Allows use of cheaper fill
material Satisfactory appearance
structures Environmental reduce damaged areas
and reduce natural material extracting
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4. REQUIREMENTS AND TECHNICAL PROPERTIES
Mainly mechanical characteristics Tensile
strength (ISO 10319) Seam tensile strength (ISO
10321) Puncture resistance (ISO 12236) Impact
test (ISO 13433) Mainly hydraulic
characteristics (for separation) Opening size
(ISO 12959) Permeability normal to the plane (ISO
11058)
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Technical Requirement as per MoSRTH
Specifications for use in subsurface drains

• Breaking load not less than 10 kN/m
• Minimum Failure strain of 10
• Apparent opening size 0.22mm 0.43 as soil
  properties
• Allow water flow _at_ not less than 10lit/sqm/sec
• Minimum puncture resistance of 200 N
• Minimum tear resistance of 150N

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Technical Requirement as per MoSRTH
Specifications for use in Highway Pavement

• Minimum Tensile strength 36.3 Kg
• Elongation 50
• Asphalt Retention 10 kg/10sqm
• Melting Point 150C
• Surface Texture- heat Bonded on one side only

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Technical Requirement as per MoSRTH
Specifications for use in Protection Works

• Aperture Rectangular, square or oval
• Colour Black
• Strength Min 10kN/m
• Elongation Max 15
• Form GR1-GG3 standards
• Life Min 8 years

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Typical Specification of NHAISeparation and
drainage
Properties Units Fabric
PHYSICAL
Grab Tensile Strength KN 0.900
Grab Tensile Elongation 50
Mullen Burst KPA 2750
Puncture KN 0.575
Trapezoid Tear KN 0.355
UV Resistance _at_hr 70/500
HYDRAULIC
Apparent Opening Size (AOS) Mm 0.150
Permittivity Sec 1.5
Flow Rate 1/min/m2 3225
Life Period Years 120
MINIMUM AVERAGE ROLL VALUES MINIMUM AVERAGE ROLL VALUES MINIMUM AVERAGE ROLL VALUES
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Typical Specification of NHAISoil Reinforcement
Sl. No. Minimum Partial FOS for calculation of 100 years long term design strength (TD) in accordance with BS-80061995 requirements Woven PP based geotextiles Woven PET based geotextiles
1 Partial FOS for deformation (at 40 C to meet less than 0.5 post construction strain requirement for retaining wall cases) 6.0 3.0
2 Partial FOS for variations in manufacture from control specimens (fm 11) 1.0 (use only MARV) 1.0 (use only MARV)
3 Partial FOS for extrapolation of creep test data (fm 12) 1.10 (10000 hours creep) 1.10 (10000 hours creep)
4 Partial FOS for construction/ installation damage (susceptibility to damage) fm 21 1.83 2.44
5 Partial FOS for potential chemical (at 40 C) and biological degradation. (Environment) fm 22 1.10 1.15
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Distribution of Geotextiles in the United Kingdom
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Distribution of Geotextile Use in South Asia
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History of Geotextiles in India

• Used commercially since early 80s
• However, during 80 90 the use was restricted
  to separation, filtration and drainage
  application for both non-woven and woven type
• Indian manufacturer like Hitkari, Tata Mills etc.
  participated in production of non-woven type for
  civil engineering application
• Major boost in usage came after 1995 with major
  ports and highway development projects.
• Application included marine protection below
  rip-raps and armour layers for separation and
  filtration for land reclamation projects.

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History of Geotextiles in India

• Application in river Training works and erosion
  control also started
• National Highways saw the application in
  drainage, embankment protection, base course
  stabilization and separation below highway
  embankments, also protection against erosion.
• Growing usage for environmental projects such as
  landfills, waste storage etc.
• MSE block walls are also a major end user,
  specially for low medium heights using geogrids
  and high strength woven Geotextile
• Now there are 10-15 non-woven as well as woven
  Geotextile manufacturer besides several
  unorganized participations

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Few Examples of NHAI Projects
Project Purpose Qty.
Visakhapatnam In Marshy/ Slushy Soils 1,08,100 sqm
Vallarpadam, Cochin Geotextile (non woven) as separation/ filtration layer 4,30,260 sqm
Tuticorin Below sub-grade 2,55,000 sqm
Paradip (i) for high embankment over land drains (ii) below sub-grade 1,04,250 sqm 40,640 sqm
JNPT Package II (SH-54 Aamra Marg) Woven geotextile below embankment 64,600 sqm
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• THANK YOU FOR YOUR ATTENTION