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Presentation by NHAI - Technical Textiles

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Presentation by NHAI - Technical Textiles Powered By Docstoc
					  TRAINING WORKSHOP ON
NON-WOVENS IN GEOTEXTILES
         AT SURAT


         5TH MARCH 2008




              BY
              S.K. PURI
              CHIEF GENERAL MANAGER - NHAI
         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)
                       Components of NHDP
Phase    Length (Km)          Cost         Focus
                              (Rs crore)
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-   588                  5208         Special Accelerated Road Development
NE
                                           Programme for NE
ICTT     17                   557          International Container Transhipment Terminal
Cochin
Total    48,688               2,41,454
Definition, Type, Process and Properties
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
Nonwoven Geotextiles
Nonwoven Geotextiles



Needle Punched nonwoven




                          Thermally bonded nonwoven
Woven Geotextiles
   Woven Geotextiles




Slit film tape-on-slit film tape




                                   Extruded tape-on-extruded tape
   Woven Geotextiles




PET multifilament woven fabric




                                 Monofil woven fabric
Knitted Geotextiles
  Knitted Geotextiles



Knitted base




                        Upper surface
            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
             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
            Hydraulic Properties
               Property                 Value Range
Porosity (non wovens)             50-95%
Present open area (wovens)        Nil to 36%
Apparent opening size ( sieve     2.0 to 0.075 mm ( # 10
  size)                              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
                           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                                      g.n.p.if <40% 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
            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
TYPICAL PHYSICAL PROPERTIES OF GEOTEXTILES
The polymers used for Geotextile




Abbreviation:
      PE: Polyethylene
      PP: Polypropylene
      PET: Polyester
Durability Test Methods for Geotextile
Functions and properties of Geotextiles
The functions of Geotextiles

§ Separator

§ Reinforcement

§ Drainage

§ Filter

§ Container

§ Energy absorber
               APPLICATIONS FOR GEOTEXTILES




  Roads            Railroads     Retaining walls   Reservoirs, dams




Liquid waste      Solid waste   Drainage systems Erosion protection
1 ROADS
1.1 APPLICATIONS IN FILTRATION AND DRAINAGE

      applications
        Pavement drains
        Sub-horizontal drains
        Curtains
        Trenches
        Settlement acceleration

                                   materials
                                    Geotextiles
                                    Geocomposite drain
                                    (PVD)
 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
 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)
1 ROADS
1.4 SEPARATION AND REINFORCEMENT MATERIALS
 SEPARATION
   GEOTEXTILES
   GEOCOMPOSITES
 REINFORCEMENT
   GEOGRIDS
   GEOTEXTILES
   GEOSTRIPS
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
2 BENEFITS OF GEOSYNTHETIC SEPARATORS
2.2 MECHANISMS



                 Avoid granular material penetration
                                Puncture resistance



                 Filtration
                          Pore size and permeability



                  Interlock advantages
                          Tensile resistance
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
3.1 PAVEMENT SYSTEMS
 3.1.1 ASPHALT REINFORCEMENT




                new roads

         Increase in fatigue life
         Reduction in rutting




          maintenance of existing roads
3.1 PAVEMENT SYSTEMS
  3.1.1 ASPHALT REINFORCEMENT
    MECHANISMS                  GEOTEXTILE




                                GEOGRID




       WITHOUT REINFORCEMENT
 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
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
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
 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”
 3.2 EMBANKMENTS OVER SOFT SOIL
 3.2.1 Applications
-basal reinforcement
-piled embankments with basal reinforcement
-reinforcement over areas prone to subsidence
3.2 EMBANKMENTS OVER SOFT SOIL
3.2.2 Basal reinforcement mechanisms




                rotational stability




                bearing capacity




               foundation extrusion
3.2 EMBANKMENTS OVER SOFT SOIL
3.2.3 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
3.2 EMBANKMENTS OVER SOFT SOIL
3.2.4 Construction
3.3 REINFORCED SLOPES AND WALLS
3.3.1 applications
landslide reparation
bridge abutment
increase working area
reduce filled area
reduce filling material
    3.3 REINFORCED SLOPES AND WALLS
    3.3.2 types
                                                   reinforcement spacing
    Walls (angle of inclination larger than 80o)
    Steep slopes
    Block walls




.
3.3 REINFORCED SLOPES AND WALLS
3.3.2 types
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
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)
     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 @ not less than
  10lit/sqm/sec
• Minimum puncture resistance of 200 N
• Minimum tear resistance of 150N
       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
       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
               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                         KN                0.575
Trapezoid Tear                   KN                0.355
UV Resistance                    %@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
                Typical Specification of NHAI
                              Soil Reinforcement
Sl.   Minimum Partial FOS for calculation of 100         Woven PP       Woven PET
No.   years long term design strength (TD) in            based          based
      accordance with BS-8006:1995 requirements          geotextiles    geotextiles
1     Partial FOS for deformation (at 40 C to meet       6.0            3.0
      less than 0.5% post construction strain
      requirement for retaining wall cases)
2     Partial FOS for variations in manufacture from     1.0 (use only 1.0 (use only
      control specimens (fm 11)                          MARV)         MARV)
3     Partial FOS for extrapolation of creep test data   1.10 (10000    1.10 (10000
      (fm 12)                                            hours creep)   hours creep)
4     Partial FOS for construction/ installation         1.83           2.44
      damage (susceptibility to damage) [fm 21]
5     Partial FOS for potential chemical (at 40 C) and   1.10           1.15
      biological degradation. (Environment) [fm 22]
Distribution of Geotextiles in the United Kingdom
Distribution of Geotextile Use in South Asia
  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.
  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
Few Examples of NHAI Projects
   Project                     Purpose                    Qty.
Visakhapatnam     In Marshy/ Slushy Soils             1,08,100 sqm

Vallarpadam,      Geotextile (non woven) as           4,30,260 sqm
   Cochin           separation/ filtration layer
Tuticorin         Below sub-grade                     2,55,000 sqm

Paradip           (i) for high embankment over land   1,04,250 sqm
                       drains                           40,640 sqm
                  (ii) below sub-grade
JNPT Package II   Woven geotextile below               64,600 sqm
(SH-54 & Aamra      embankment
   Marg)
THANK YOU FOR YOUR ATTENTION

				
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