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

2. 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)

3. Components of NHDP Focus
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
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)
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

4. Definition, Type, Process and Properties

5. What is a Geotextile? Types of Geotextile Non-woven Woven
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

6. Nonwoven Geotextiles

7. Needle Punched nonwoven
Nonwoven Geotextiles
Needle Punched nonwoven
Thermally bonded nonwoven

8. Woven Geotextiles

9. Woven Geotextiles Slit film tape-on-slit film tape
Extruded tape-on-extruded tape

10. Woven Geotextiles
PET multifilament woven fabric
Monofil woven fabric

11. Knitted Geotextiles

12. Knitted Geotextiles
Knitted base
Upper surface

13. 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

14. Mechanical Properties
Property
Value Range
Compressibility
Nil to high
Tensile strength (grab) kN
Tensile strength ( wide width)
9-180 kN/m
Confined tensile strength
kN/m
Seam strength
50-100% of tensile
Cycle fatigue strength
Burst strength
k Pa
Tear strength N
Impact strength J
Puncture strength N
Friction behavior
60-100% of soil friction
Pullout behavior
50-100% of geotextile strength

15. 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 mm ( # 10 to # 200)
Permittivity
s-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

16. Endurance Properties Property Value Range Installation damage
0.70% of fabric strength
Creep response
g.n.p.if <40% strength is being used
Confined creep response
g.n.p.if <50% strength is being used
Stress relaxation
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
appear to be acceptable
g.n.p. – generally no problem, m.b.e. – must be evaluated

17. 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
Sunlight ( UV) degradation
Major problem unless protected
Synergistic effects
m.b.e.
General aging
Actual record to date is excellent

18. TYPICAL PHYSICAL PROPERTIES OF GEOTEXTILES

19. The polymers used for Geotextile
Abbreviation:
PE: Polyethylene
PP: Polypropylene
PET: Polyester

20. Durability Test Methods for Geotextile

21. Functions and properties of Geotextiles

22. The functions of Geotextiles
Separator
Reinforcement
Drainage
Filter
Container
Energy absorber

23. APPLICATIONS FOR GEOTEXTILES
Roads
Railroads
Retaining walls
Reservoirs, dams
Liquid waste
Solid waste
Drainage systems
Erosion protection

24. 1 ROADS 1.1 APPLICATIONS IN FILTRATION AND DRAINAGE
Pavement drains
Sub-horizontal drains
Curtains
Trenches
Settlement acceleration
materials
Geotextiles
Geocomposite drain
(PVD)

25. 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

26. 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)

27. 1 ROADS 1.4 SEPARATION AND REINFORCEMENT MATERIALS
GEOTEXTILES
GEOCOMPOSITES
REINFORCEMENT
GEOGRIDS
GEOSTRIPS

28. 2 BENEFITS OF GEOSYNTHETIC SEPARATORS 2.1 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

29. 2 BENEFITS OF GEOSYNTHETIC SEPARATORS 2.2 MECHANISMS
Avoid granular material penetration
Puncture resistance
Filtration
Pore size and permeability
Interlock advantages
Tensile resistance

30. 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

31. 3.1 PAVEMENT SYSTEMS 3.1.1 ASPHALT REINFORCEMENT
new roads
Increase in fatigue life
Reduction in rutting
maintenance of existing roads

32. 3.1 PAVEMENT SYSTEMS 3.1.1 ASPHALT REINFORCEMENT
MECHANISMS
GEOTEXTILE
GEOGRID
WITHOUT REINFORCEMENT

33. 3.1 PAVEMENT SYSTEMS 3.1.1 ASPHALT REINFORCEMENT
Note:
thin nonwoven geotextiles can be used when
cracking still keeps the aggregates interlocking
(tensile characteristics are not required)
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

34. 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

35. 3.1 PAVEMENT SYSTEMS 3.1.3 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

36. 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”

37. 3.2 EMBANKMENTS OVER SOFT SOIL 3.2.1 Applications
-basal reinforcement
-piled embankments with basal reinforcement
-reinforcement over areas prone to subsidence

38. 3.2 EMBANKMENTS OVER SOFT SOIL 3.2.2 Basal reinforcement mechanisms
rotational stability
bearing capacity
foundation extrusion

39. 3. 2 EMBANKMENTS OVER SOFT SOIL 3. 2
3.2 EMBANKMENTS OVER SOFT SOIL 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

40. 3.2 EMBANKMENTS OVER SOFT SOIL 3.2.4 Construction

41. 3.3 REINFORCED SLOPES AND WALLS 3.3.1 applications
landslide reparation
bridge abutment
increase working area
reduce filled area
reduce filling material

42. 3.3 REINFORCED SLOPES AND WALLS 3.3.2 types
reinforcement spacing
Walls (angle of inclination larger than 80o)
Steep slopes
Block walls .

43. 3.3 REINFORCED SLOPES AND WALLS 3.3.2 types

44. 3.3 REINFORCED SLOPES AND WALLS 3.3.3 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

45. 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)

46. Breaking load not less than 10 kN/m Minimum Failure strain of 10%
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 not less than 10lit/sqm/sec
Minimum puncture resistance of 200 N
Minimum tear resistance of 150N

47. Minimum Tensile strength 36.3 Kg Elongation 50%
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

48. Aperture : Rectangular, square or oval Colour : Black
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

49. Typical Specification of NHAI Separation and drainage
Properties
Units
Fabric
PHYSICAL
Grab Tensile Strength KN
0.900
Grab Tensile Elongation % 50
Mullen Burst
KPA
2750
Puncture
0.575
Trapezoid Tear
0.355
UV Resistance
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

50. Typical Specification of NHAI Soil Reinforcement
Sl. No.
Minimum Partial FOS for calculation of 100 years long term design strength (TD) in accordance with BS-8006:1995 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) 3
Partial FOS for extrapolation of creep test data (fm 12)
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

51. Distribution of Geotextiles in the United Kingdom

52. Distribution of Geotextile Use in South Asia

53. 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.

54. 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 non-woven as well as woven Geotextile manufacturer besides several unorganized participations

55. Few Examples of NHAI Projects
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

56. THANK YOU FOR YOUR ATTENTION