jute geo-textiles applications of jute geo –textiles - a presentation by the jute manufactures...
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Applications ofJute Geo –Textiles
- A presentation by The Jute Manufactures Development Council
Jute
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Technical textiles that improve engineering performance of the soil
Either made of synthetic polymers (petrochemical derivatives) or of natural fibres (jute, coir)
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JGT - the forerunner of man made GT
Use of jute for solving soil-related problems is not a new concept.
Jute hessian was applied successfully on Strand Road at Kolkata as early as in 1934 and in Myanmar during the 2nd World War
First concerted effort to promote use of Jute Geotextile took off in 1980s
JMDC has published a manual on application of JGT in Civil engineering
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USP of jute
High moisture absorbing capacity
Excellent drapability (the best of all GTs)
High initial tensile strength
Low extension at break
High roughness co-efficient
High spinnability
Bio-degradable; soil nourisher
Renewable resource, easily available
Economical
Eco-friendly
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lesJGT – Basic functions
Separation
Filtration
Drainage
Initial reinforcement.
Additionally, it helps in providing biotechnical support to the soil.
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Separation
Segregates two layers, preventing intermixing
Facilitator to natural consolidation of soil
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Filtration
Two contrasting functions -
soil retention
allowing pore-water through and along the fabric
Addressing 2 related phenomena –
clogging
blocking.
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Drainage
Acts as a drain within its own thickness.
Permittivity and Transmittivity of JGT are high
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Initial Reinforcement
Acts against rotational slides, lateral dispersion and vertical subsidence
Exerts confining action on soil
Partially absorbs effective stress, preventing shear failure.
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Civil engineering applications of JGT
Slope management
Protection of river bank
Strengthening of road
Stabilizing embankments
Prevention of railway track subsidence
Consolidation of soft soil
Control of surface soil detachment
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1.Slope management with JGT
Slopes erode due to:
Flow of rain water
Severe wind
Can be controlled by reducing the velocity of surface run-off.
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1.Slope management with JGT
Open weave JGT with 3D construction
controls slope erosion :
Creates an array of micro-barriers against the
overland flow, reducing velocity.
Effects partial storage due to capacity to absorb
water
Entraps detached soil particles.
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1.Slope management with JGT
Absorbs water upto about 5 times its dry weight
Stores 0.44 litres per sqm on 1: 2 slope
Promotes quick growth of vegetation.
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2. Protection of river banks
Causes of river bank erosion
Erodable bank soil
Strong current
Large fluctuations in water level
Waves uplift pressure
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2. Protection of river banks
Granular / fabric Filter should address 5 basic criteria –
Soil-tightness Prevention of differential over pressure across
the filter Separation of bank-soil from the overlying filter Strength to withstand installation hazards Effectiveness during its design life
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2. Protection of river banks
Conventional Granular Filter Two – layer construction
Inner core and outer layer.
Disadvantages :
No separation between layers
Results in inter-penetration of layers
Reduction in design thickness of layers
Permittivity is impaired
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2. Protection of river banks
Fabric Filter
JGT, a natural fabric filter, an effective substitute
of conventional granular filter. Can satisfy all the requirements of filter needed
for protection of river banks.
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2. Protection of river banks
Survivability of JGT depends on--
Careful storage, handling, transportation, laying
on level surface
Guard against puncture by falling aggregates
Guard against soil-slurry at the time of laying
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2. Protection of river banks
Durability :
In unidirectional flow - 2 season cycles are sufficient for filter-cake formation & natural stability
In flow – reversals - with a moderate cycle time, a longer time is needed ( > 4 season – cycles )
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Problems of conventional practice
Availability of the right filter materials in time.
Control on quality and workmanship.
Time of execution.
Environmental concerns due to quarrying/ mining for
filter materials.
Thus a need for an economical and effective substitute.
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3. JGT in road construction
Causes of failure of roads :
Inadequate pavement thickness
Traffic load & intensity
Low bearing capacity of sub grade
Intermixing of sub-base and sub grade
Insufficient drainage of surface and sub-surface water
Leading to “mud pumping”
Permeable wearing course
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3. JGT in road construction
How can JGT help?
Enhances the CBR of the sub grade
Prevents intermixing of sub grade and sub-base
Facilitates filtration & drainage in the sub-surface zone
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3. JGT in road construction
Guidelines for designing a new road with JGT
CBR to be taken as 1.5 times the control value of CBR.
Woven JGT should be selected in conformity with the average particle size distribution
Provisions of sub-surface drainage should be made with non-woven JGT concurrently.
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3. JGT in road construction
Note :
Choice of JGT also depends on the allowable rut depth which is a factor of the level of service
expected of a road vis-à-vis the level of its maintenance
Porometry range: 150 to 400 microns Tensile strength: 25 kN/m should serve the purpose [recommended by the CFGG Manual (French).]
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4. Stability of embankments
Expansive or compressive soils used as fills in embankments may lead to:
Vertical subsidence Lateral dispersion Downslope migration Rotational slides (slip circle failure)
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4. Stability of embankments
Absorbs stress and strain induced due to moving loads on embankments
Soil - JGT friction acts as a medium of transference of the induced stress and strain
JGT can directly reinforce the soil mass in an embankment only during its useful lifespan
Soil is otherwise stabilized due to separation, filtration and drainage effects
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Basal reinforcement with JGT for any new embankment is effective
JGT can also be used in successive layers of an embankment and may be folded at the fringes for side restraint
PRECAUTION
Prevent ingress of water into an embankment Drain out entrapped water from an
embankment for which JGT encapsulated
concealed drains may be constructed
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5. Prevention of railway track subsidence
Causes of railway track subsidence
Erosion pumping
Intermixing of ballast and subgrade
Entrapped water within embankment
Surficial erosion erosion of cess width
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5. Prevention of railway track subsidence
Solution Use of JGT (woven + non-woven) on subgrade
after removal of ballast layer
Use of JGT encapsulated rubble drains within embankment
Reshaping of embankment profile – rebuilding the cess
Protection of slope with open mesh JGT
Vegetation on slope
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6. Consolidation of soft soil
Pre-fabricated Vertical Jute Drain (PVJD)
Better substitute of sand - drains
Drains out water by capillary action Standard prefab vertical jute drains with jute/coir wicks available Equivalent drain diameter and its zone of influence may be calculated (as per Runesson et al,1977) to determine the drain spacing
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7. Control of surface soil detachment
JGT also:
Reduces erodability co-efficient of soil
Attenuates extremes of temperature Protects soil and seeds from direct exposure Controls dehydration of soil Allows air and light Adds nutrients to the soil and acts as mulch on Biodegradation
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7. Control of surface soil detachment
Vegetation as bio-engineering support
Vegetation Dissipates KE of rain drops Is a receptor of moisture Attenuates wind effects Reduces velocity of surface run off Ensures soil attachment with roots Improves soil – permeability
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7. Control of surface soil detachment
Choice of vegetation is important
JGT improves micro-climatic conditions
Enhances organic matter levels
Thus an excellent catalyst for quick growth of
vegetation
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Durability of JGT
Loss of strength of JGT after a year is NOT a deterrent – by that time, JGT provides a self-sustaining sub-grade for most soils
The gain in strength of the sub-grade compensates the loss of strength of JGT within the same time frame (ibid & JU 2005)
With the passage of time soil dependence on JGT for stability decreases
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Is bio-degradability of JGT a technical disadvantage?
Consolidation of soil by JGT takes about a year
Necessity of GT ceases thereafter.
Degradability of JGT after this period is thus an advantage
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Comparison between JGT &SGT in respect of properties(for woven type)
JGT has a higher C factor than SGT 0.005 in a slope of 1:1.5 0.004 in a slope of 1:3
Narrow strip tensile strength – For JGT – 30 kN/m (warp) x 20 kN/m (weft) usually For SGT – can customise to any strength
Strain at failure for JGT – 7% to 9% (SGT – usually 23%)
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Comparison between JGT &SGT in respect of properties (for woven type)
Elongation at break for JGT – 11 % to 13 %
JGT has a high initial tangent modulus (comparable to SGT)
JGT has a breaking strength of 33 kN/m (warp) and 28 kN/m (weft)
JGT offers a greater interfacial friction than SGT
JGT has greater transmittivity than SGT
Permittivity of JGT is comparable to that of SGT
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Comparative costs of JGT with Synthetic Geo-textile
Open mesh JGT – Rs. 9 - 10 per sq.m. Open mesh GeoSynthetic - Rs. 30 per sq.m.
Woven JGT (treated with rot resistant chemical and bitumen - Rs. 40 - 45 per sq.m. Woven GeoSynthetic – Rs. 80 – 90 per sq.m.
Non woven JGT – Rs. 15 - 19 per sq.m. Non woven GeoSynthetic– Rs. 45 -
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Comparative Estimated Cost ( for West Bengal)
Bank protection of rivers with conventional granular filters – Rs.65 – 70 / sq.m.
Bank protection of rivers with JGT and armour overlay – Rs.60 – 65 / sq.m. New bank protection of rivers with SGT – Rs. 75 / sq.m.
New road construction with GeoSynthetics - Rs. 57 lac / km (Class AA loading, 7 m. wide)
New road construction with JGT – Rs. 55 lac / km (Class AA loading, 7 m. wide)
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Easily available
Can be tailor made to meet the criteria of retention and permeability.
Precise control on quality and workmanship possible.
Quicker execution time.
More drapability than any other geo-textile.
Provides a sustainable and Eco-compatible solution.
Conducive natural protection against erosion through quick growth of vegetation cover.
Advantages Of JGT – in summary
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Use of JGT in asphaltic overlay for prevention of reflection cracks.
Developing a paving fabric as a substitute of masticasphalt.
Turf reinforcing mats with JGT.
Fabriforms
“Jutecrete”
Development of water-resistant & stronger JGT.
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Standards/Normative References
IS 14986:2001—
Guidelines for application of Jute Geo-textiles for rain water erosion control in road & railway embankments and hill slopes
RDSO, Ministry of Railways –
Guideline no GE:G1 (July 2003)—Guidelines for earthwork in railway projects
Indian Roads Congress—
Specifications for road & bridge works (2001) & Recommended practice for treatment of embankment slope & erosion control (1991)
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Case Studies in Civil EngineeringCase Studies in Civil Engineering
Case Studies
Case Studies in AgricultureCase Studies in Agriculture
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Case Studies In Civil Engineering
Construction of highway embankment on soft marine soil using jute Geo-Textile at Kakinada port – Andhra Pradesh
Widening and strengthening of Munshirhat – Rajpur Road, West Bengal.
Application of JGT for mine-spoil stabilisation in Uttaranchal
Control of bank erosion naturally – a pilot project in Nayachara Island (West Bengal) on the River Hoogly.
Prevention of railway track subsidence with jute Geo-Textile – a case study under Eastern Railway.
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Project I
Name of the project
Construction of highway embankment on soft marine soil using jute Geo-Textile at Kakinada Port – Andhra Pradesh
Objective
Reinforcement of the highway embankment with the help of jute Geo-Textile by minimising post-construction settlement, lateral spreading of fill material etc.
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Laying of Jute Geotextile
Road before giving final shape
Leveling in progress
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Properties of Jute Geo-Textile Used
Thickness 3 mm
Weight 750 gsm
Tensile strength 20 kn/m
Elongation at break 3%
Puncture resistance 350 n
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Water content, void ratio and compression index decreased while dry density and CBR value of the sub-grade soil increased by use of jute Geo-Textile.
Jute Geo-Textile appeared to be very effective even in weak sub-grade soils in reducing their compressibility and increasing their strength as reflected from the good performance even after a lapse of 7 years.
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Name of the project
Widening and strengthening of Munshirhat – Rajpur Road, West Bengal.
Objective
Strengthening of the widened portion of the existing black top road on both sides with use of jute Geo-Textile for controlling settlement.
Project II
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Widening of Munshirhat – Rajpur Road - JGT is laid on the sub-grade.
Consolidation of brick metal laid over JGT on
widened portion
Finished Road after widening.
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Properties Of Rot Proof Jute Geotextile Used
Properties Value
Weight (g / m2) at 20% M.R. 760
Threads / dm (MD X CD) 102 x 39
Thickness (mm) 2
Width (cm) 76
Strength (kN/m) (MD X CD) 20 x 20
Elongation at break (%) (MD x CD) 10 x 10
Pore size (090) micron 300
Water permeability at 10 cm water head (l / m2 / s) 50
Puncture resistance (N / cm2) 380
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Conclusion
The average CBR value of the sub-grade before application of JGT was 3.5%.
The sub-grade gained strength by application of JGT and reached a CBR value of 6.0%.
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Name of the project
Application of JGT for mine-spoil stabilisation in Uttaranchal.
Objective
Stabilisation of slope by checking the slide of soil, debris and boulders during heavy rains and restoration of the vegetative cover destroyed due to mining activities.
Project III
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Mine Spoil heap at Sahashradhara
Laying of Open weave JGT on mine spoil heap
Sprouting of plants after laying of JGT.
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Properties Of Jute Geotextile Used
Properties Value
Weight (gsm) at 20% moisture regain 500
Threads / dm (MD x CD) 6.5 x 4.5
Thickness (mm) 4
Width (cm) 122
Open area (%) 50
Strength (kN / m) (MD x CD) 10 x 7.5
Water holding capacity ( as % of dry weight) 500
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Vegetation establishment
Yield of grass was 5 times than that under control conditions.
Moisture improvement
Delayed wilting point (7 days instead of 3 days under control conditions after a rain fall of 20 mm).Retention of moisture at a depth of 30 cm after a month.
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Velocity of surface run off from 57% to 37%Flood peak was delayed by 20 minutesSoil erosion was reduced to 8 ton/ha
Water Resource Improvement
Water availability in the water shed improved
Soil Improvement
Increase in carbon content and P2O5
Decrease in CaCo3 and PH over a period of 7 years
Findings & Conclusion
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Name of the Project
Control of bank erosion naturally – a pilot project in Nayachara Island (West Bengal) on the River Hoogly.
Objective
To protect the island from severe erosion of its western bank hugging the River Hoogly.
Project IV
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Eroded bank of Nayachara Island
JGT was laid on eroded bank of Nayachara Island
Performance of JGT on erosion control at Nayachara Island. [Photograph taken 11 years after completion of work.]
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les Material : D.W.Twill – 8 X 12 850 gsm(grey)
1538gsm(bitumen treated )
Thickness 2.83 mm
Breaking Strength (kN / m) 33.1 (Warp)
28.2 (Weft)
Elongation at Break (%) 11.8 (Warp)
13.5 (Weft)
Puncture Resistance (Kgf / cm2) 37.9
Air Permeability (m3 / m2 / min) 16.2
Water Permeability at 10 cm water head (I / m2 / sec)
20.4
Pore size (microns) 150
Properties Of Jute Geo-Textile
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No subsidence/settlement was observed after 11 years despite considerable reduction in strength and porometric features of JGT.
Durability of JGT beyond one and half years, even under persistent flow adversities, proved to be redundant due to catalytic function of JGT.
Use of JGT in river bank protection proved to be an effective alternative to conventional methods in respect of capital investment and recurring maintenance cost.
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Name Of The Project
Prevention of railway track subsidence with jute Geo-Textile – A case study under Eastern Railway.
Objective
To restore the settled track to the desired level and improving the bearing capacity of the fill. The track has been undergoing persistent settlement for the last 25 years. Short term remedial intervention did not work.
Project V
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Subsidence of Railway Track at Gurap section of Howrah – Bardhaman Chord line
Process of laying JGT under Railway Track
Completed Railway Track after application of JGT
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Properties Of Different Types Of Jute Geo-Textile Used
Properties Woven (Treated)
Non-Woven
Open Weave
WEIGHT (g/m2) AT 20% MR (MOISTURE REGAIN)
THREADS/dm (MD X CD)
THICKNESS (MM)
WIDTH (CM)
STRENGTH (kN/m) (MD X CD)
ELONGATION AT BREAK % (MD X CD)
PORE SIZE (090) MICRON
PERMITTIVITY AT 10cm WATER HEAD (I/m2/s)
PUNCTURE RESISTANCE (N)
WATER HOLDING CAPACITY (% ON DRY WT.)
OPEN AREA (%)
1200
102 X 39
2
76
21 x 21
10 x 10
150
20
400
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1000
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8
150
6 x 7
20 x 25
300
─
─
─
500
6.5 X 4.5
4
122
10 x 7.5
─
─
─
─
500
50
Woven JGT- for sub-grade improvement
Non-woven JGT-for concealed drains
Open weave JGT-for slope protection
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The affected stretch did not undergo any settlement even after 3 seasons.
No interim remedial intervention was necessary for the first time in the last 25 years.
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Case Studies In Agriculture
Field trial with woven & non-woven jute agro-textile for studying erosion control and other allied features.
Field trial with jute agro-textile in tea estate – weed management
Study of the effectiveness of jute agro-textile in plant-growth in a semi arid zone in West Bengal.
Study of the efficacy of jute sleeves in raising of seedlings compared to conventional poly-sleeves.
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Project I
Name of the project
Field trial with woven & non-woven jute agrotextile for studying erosion control and other allied features.
Objective
To study surficial soil erosion control, assessment of nutrient loss and agro-mulching effects by using appropriate jute agrotextile.
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Open Weave JAT for Erosion Control
Open Weave JAT laid between the rows of young plants
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Properties Of Jute Agro-Textile
PROPERTIES OPEN WEAVE
TYPE - I TYPE - II
WEIGHT (g/m2) 400 300
THICKNESS (mm) 3 3
OPEN AREA (%) 40 60
THREADS / dm (WarpX Weft) 34 X 15 17 X 4.6
WIDTH (cm) 122 122
WATER ABSORPTION CAPACITY (%) 500 400
TENSILE STRENGTH (kN/m) [ Warp X Weft] 12 X 10 10 X 7.5
ELONGATION AT BREAK (%) [ Warp X Weft] 10 X 12 10 X 15
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Jute agro-textile was effective when used in combination with green crop in reducing soil erosion and controlling nutrient loss.
Type–I jute agro-textile was found more effective than Type–II jute agro-textile.
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Project II
Name Of The Project
Field trial with jute agro-textile in tea estate – weed management
Objective
To study the effectiveness of jute agro-textile in weed suppression.
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Weed management in Tea garden with non woven JGT
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Properties Of Jute Agro-Textile
PROPERTIES
NON-WOVEN
TYPE - I TYPE - II
WEIGHT (g/m2) 500 750
THICKNESS (mm) 6 8
OPEN AREA (%) 0 0
WIDTH (cm) Upto 150 Upto 150
LENGTH (M) 50 50
WATER ABSORPTION CAPACITY (%) 650 700
TENSILE STRENGTH (kN/m) [Warp X Weft] 5 X 6 7 X 8
ELONGATION AT BREAK (%) [ Warp X Weft] 20 X 25 25 X 30
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Non-woven jute agro-textile could reduce weed by 65%.
Addition of weedicides could enhance the extent of suppression by a further 13% maximum.
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Project III
Name Of The Project
Study of the effectiveness of jute agro-textile in plant-growth in a semi-arid zone in West Bengal.
Objective
Quantification of difference in growth of plants with & without jute agro-textile in a semi-arid zone.
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Growth of plant with JAT
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Properties Of Jute Agro-Textile
PROPERTIES
WOVEN
TYPE - I TYPE - III
WEIGHT (g/m2) 400 300
THICKNESS (mm) 3 2
OPEN AREA (%) 40 70
THREADS/dm [ WARP X WEFT ] 34 X 15 11 X 12
WIDTH (cm) 122 122
WATER ABSORPTION CAPACITY (%) 500 350
TENSILE (kN/m) [ Warp X Weft ] 12 X 10 10 X 10
ELONGATION AT BREAK (%) [ Warp X Weft ] 10 X 12 12 X 12
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The growth of plants was found to be more pronounced with Type-I jute agro-textile and was almost double the growth under control conditions.
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Project IV
Name Of The Project
Study of the efficacy of jute sleeves in raising of seedlings compared to conventional poly-sleeves.
Objective
To study the comparative advantages in using jute sleeves in place of poly sleeves for holding soil bulbs of seedlings.
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lesJute Sleeve for growth of sapling
Seedlings in conventional poly-sleeves
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Specification Of Jute Sleeves
FABRIC USED – 272 gsm HESSIAN
SIZE OF SLEEVE – 23 cm x 15 cm
WEIGHT / SLEEVE – 26 g.
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Faster & better growth of seedlings due to better aeration of roots of seedlings, evening out of temperature extremes, non-formation of ice within the sleeves and spread of roots through fine openings of the jute sleeves.
High survival rate (90%).
No extraction at the post plantation stage was necessary, unlike in the case of poly sleeves.
Jute sleeves are evidently superior to poly-sleeves in performance, installation and after care.
The cost of jute sleeves is, of course, higher than poly sleeves.
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JGT basically acted as catalyst or change-agent in improving soil behaviour.
Drainage of water/moisture from soil is a critical function.
Need for proper design of JGT with right porometry and transmittivity / permittivity.
Durability of JGT beyond two season cycles has hardly any technical significance.
Inference
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Effectiveness of JAT as weed suppressor, as agro-mulch, temperature conditioner and humidity regulator is established.
JAT’s role as growth facilitator of plants even in semi-arid zones is confirmed.
Advantages of jute sleeves over poly sleeves are also established.
Inference
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Thank You.
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Dam Storage
- - - - - - -- -
- - - - - - - - -
L
Storage) β
Weft of open mesh JGT
StorageD
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Soil erosion process on a slope
RAIN
- - - -- - - - -
XC
belt of no erosion
FLOWactive erosion
deposition of sediments
D
ad
bb’e
c’c
material in suspension
overland flow
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Installation of jute geo-textile
Direction of laying
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Fixing nail
Graded slope
Grass plant
Toe anchor(150 mm x 150mm)
150
Shoulder anchor(150 mm x 150mm)
150 mm
50 mm
Fixing nail(II Gauge wire)
+
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2. Protection of river banks
Design aspects of JGT : Basic equation – On < dn d90 or d50
O90 or O95
If On is increased, piping will occur
If On is reduced, clogging nay take place
A judicious compromise has to be made between
Porometry and Permittivity of JGT
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2. Protection of river banks
Design aspects of JGT
Several empirical options
PIANC(1987) If d40 < 0.60 mm, O90 bet 300 and 1500 micron > 0.60 mm, O90 bet 500 and 2000 micron
AASHTO(1990) AOS (O90) < 600 micron if d50 > 0.075 mm < 300 micron if d50 < 0.075 mm
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2. Protection of river banks
Design aspects of JGT
Clogging – mechanical lodging of soil grains on JGT & chemical i.e.
deposition of chemicals like iron & bacteria from groundwater / soil.
Co- eff. of permeability of the base-soil ks
kg > ks
permittivity of JGT
For unidirectional flow – kg ≈ 10 ks for low hydraulic gradients (<5)
For reversing flow – kg ≈ 100 ks
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2. Protection of river banks
Design aspects of JGT
Clogging potential may be tested by conducting
Gradient Ratio Test as per ASTM – D5101 – 90 or by
Hydraulic Conductivity (HCR Test) as per ASTM D
5567.
Clogging – probability when flow rate continues to
decrease with time
Piping – probability when flow rate continues to
increase with time
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3. JGT in road construction
Some Salient Findings
Percentage elongation at break of JGT – significantly lower than that of geo-synthetics (maximum 15% as against more than 50 % for SGT) (Ramaswamy & Aziz – 1989)
Substantial reduction (more than 50%) in rut depth under dynamic load tests with JGT (Ramaswamy & Aziz – 1989)
Improvement of settlement behaviour by using JGT as well as improvement of CBR
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Effect of Jute Fabric on compaction characteristics of subgrade soil
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Studies by Ramaswamy & Aziz (1989) on clayey subgrade
Table - I
22
42
10
30
8
26
c) Strain at failure (%)
i) without JGT
ii) with JGT
36
65
45
115
110
330
b) Undefined Compressive Strength (kN/m2)
i) without JGT
ii) with JGT
353025a) Water Content (%)
5.0
8
20
2.6
4.5
3.5
5.2
4.7
6.8
b) CBR (%)
i) without JGT
ii) with JGT
353025a) Water Content (%)
Table - II
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Filter cake formation
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