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

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Presentation on theme: "TRAINING WORKSHOP ON NON-WOVENS IN GEOTEXTILES AT SURAT BY S.K. PURI CHIEF GENERAL MANAGER - NHAI 5 TH MARCH 2008."— Presentation transcript:

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

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 PhaseLength (Km)Cost (Rs crore) Focus IBal. 1738Bal Golden quadrilateral (GQ)- connecting Delhi- Mumbai-Chennai- Kolkata-Delhi Total Length 5846 IIBal. 6736Bal North South& East west Corridors (NS-EW) Total Length 7300 III12,10980,626 State capital connectivity,High traffic density, Imp.centers of tourism &economic activity IV20,00027,800 Widening & Strengthening to 2-lane with Paved shoulders V6,50041,210 Six laning of high density corridors VI1000 Km16,680 Expressway for connecting important places VII(Being identified)16,680 Ring roads to cities, flyovers, by-passes SARDP- NE Special Accelerated Road Development Programme for NE ICTT Cochin International Container Transhipment Terminal Total48,6882,41,454

4 Definition, Type, Process and Properties

5 Any permeable textile natural or synthetic, used with foundation soil, rock, earth, or any other geotechnical engineering related material. What is a Geotextile? Types of Geotextile Woven Non-woven

6 Nonwoven Geotextiles

7 Needle Punched nonwoven Thermally bonded nonwoven Nonwoven Geotextiles

8 Woven Geotextiles

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

10 Monofil woven fabric PET multifilament woven fabric Woven Geotextiles

11 Knitted Geotextiles

12 Knitted base Upper surface Knitted Geotextiles

13 Physical Properties PropertyValue range Specific gravity0.9 – 1.7 Mass per unit area135 – 1000 g/m 3 Thickness0.25 – 7.5 mm StiffnessNil – 25,000 mg-cm

14 Mechanical Properties PropertyValue Range CompressibilityNil to high Tensile strength (grab) kN Tensile strength ( wide width)9-180 kN/m Confined tensile strength kN/m Seam strength50-100% of tensile Cycle fatigue strength50-100% of tensile Burst strength k Pa Tear strength N Impact strength J Puncture strength N Friction behavior60-100% of soil friction Pullout behavior50-100% of geotextile strength

15 Hydraulic Properties PropertyValue 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 load0,01-3.0s -1 Transmissivity0.01 to 2.0 x10-3m 2 /min Soil retention: turbidity curtainsMust be evaluated Soil retention: silt fencesMust be evaluated

16 Endurance Properties PropertyValue Range Installation damage0.70% of fabric strength Creep responseg.n.p.if <40% strength is being used Confined creep responseg.n.p.if <50% strength is being used Stress relaxationg.n.p.if <40% strength is being used Abrasion50-100% of geotextile strength Long-term cloggingm.b.e.for critical conditions Gradient ratio cloggingm.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 PropertyValue Range Temperature degradationHigh temperature accelerates degradation Oxidative degradationm.b.e. for long service lifetimes Hydrolysis degradationm.b.c. for long service lifetimes Chemical degradationg.n.p.unless aggressive chemicals Radioactive degradationg.n.p. Biological degradationg.n.p. Sunlight ( UV) degradationMajor problem unless protected Synergistic effectsm.b.e. General agingActual 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  Energy absorber  Container

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

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

25 1 ROADS 1.2 APPLICATIONS IN EROSION CONTROL MATERIALS GEOTEXTILES Detain carried particles: during construction, before vegetation or under wind effects SUPERFICIAL EROSION silt fences

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 SEPARATION GEOTEXTILES GEOCOMPOSITES REINFORCEMENT GEOGRIDS GEOTEXTILES GEOSTRIPS

28 2 BENEFITS OF GEOSYNTHETIC SEPARATORS 2.1 TYPICAL APPLICATIONS -prevent contamination -avoid build-up of pore pressure -avoid loss of granular material Located at the interface between soil and aggregate 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 ASPHALT OVERLAY BASE/SUBGRADE 3.2 EMBANKMENTS OVER SOFT SOILS 3.3 SLOPES AND WALLS

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

32 3.1 PAVEMENT SYSTEMS ASPHALT REINFORCEMENT MECHANISMS GEOTEXTILE GEOGRID WITHOUT REINFORCEMENT

33 3.1 PAVEMENT SYSTEMS ASPHALT REINFORCEMENT thin nonwoven geotextiles can be used when cracking still keeps the aggregates interlocking (tensile characteristics are not required) protector layer - retards crack propagation by deviation moisture barrier – increases life time after cracking Note: The asphalt impregnated geotextile do not acts as a reinforcement, but as a protector layer and a moisture barrier.

34 3.1 PAVEMENT SYSTEMS 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 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 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 Applications -basal reinforcement -piled embankments with basal reinforcement -reinforcement over areas prone to subsidence

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

39 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 Construction

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

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

43 3.3 REINFORCED SLOPES AND WALLS types

44 3.3 REINFORCED SLOPES AND WALLS 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 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 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 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 PropertiesUnitsFabric PHYSICAL Grab Tensile StrengthKN0.900 Grab Tensile Elongation%50 Mullen BurstKPA2750 PunctureKN0.575 Trapezoid TearKN0.355 UV HYDRAULIC Apparent Opening Size (AOS)Mm0.150 PermittivitySec1.5 Flow Rate1/min/m23225 Life PeriodYears120 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 1Partial FOS for deformation (at 40 C to meet less than 0.5% post construction strain requirement for retaining wall cases) Partial FOS for variations in manufacture from control specimens (fm 11) 1.0 (use only MARV) 3Partial FOS for extrapolation of creep test data (fm 12) 1.10 (10000 hours creep) 4Partial FOS for construction/ installation damage (susceptibility to damage) [fm 21] Partial FOS for potential chemical (at 40 C) and biological degradation. (Environment) [fm 22]

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 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 History of Geotextiles in India

55 Few Examples of NHAI Projects ProjectPurposeQty. VisakhapatnamIn Marshy/ Slushy Soils1,08,100 sqm Vallarpadam, Cochin Geotextile (non woven) as separation/ filtration layer 4,30,260 sqm TuticorinBelow sub-grade2,55,000 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


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