JGT Presentation by Ms. Rumki Saha, NJB

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Transcript JGT Presentation by Ms. Rumki Saha, NJB

Jute Geo-Textiles
ECONOMICAL & ENVIRONMENTAL
ADVANTAGES OF USING JUTE GEOTEXTILE
IN RURAL ROAD, RIVER BANK PROTECTION
AND HILL SLOPE MANAGEMENT
Presented by
NATIONAL JUTE BOARD (PEA)
Jute Geo-Textiles
CONTENTS
1. ECONOMICS
i. Low Volume Road Construction
ii. River Bank Protection
iii. Hill Slope Management
2. ENVIRONMENTAL ASPECTS
i. Life cycle assessment of jute product
ii. Low Volume Road Construction
iii. River Bank Protection
iv. Hill Slope Management
v. Eco-compatibility & Socio-economic values of jute
Jute Geo-Textiles
JGT in Road Construction
 JGT or all GTs act as change agents triggering the
consolidation process and gradual development of
effective stress.
In all cases JGT treated Sub-grade happens to
enhance CBR by 150 – 300% over control value.
Reduced base course thickness (due to increased
CBR) offsets cost of JGT.
 Scope of savings in initial construction [ based on
Handbook of ‘Geosynthetics case studies by Indian
Technical Textiles Association (ITTA)]
Jute Geo-Textiles
JGT in Road Construction
The following results are revealing a) Water Content (%)
20
25
30
35
b) CBR (%)
i) without JGT
ii) with JGT
5.0
8
4.7
6.8
3.5
5.2
2.6
4.5
Source – Ramaswamy & Aziz(1989)
Natural Soil CBR (%)
Improved soil CBR (%)
Unsoaked specimen
Soaked specimen
Unsoaked specimen
Soaked specimen
2.10
1.61
6.03
4.78
Source – A Sreerama Rao (2003)
Jute Geo-Textiles
ASSUMPTIONS
Assumptions For Computation of Initial Construction Cost –
1. CBR of sub-grade soil : 3 – 4 %
2. Considering Enhancement of CBR of sub-grade soil by 1.5
times : 5 – 6 %
3. Cumulative Traffic ESAL : 60,000 – 1,00,000
4. Length of Pavement : 1000 m
5. Carriageway Width of Pavement : 3.75 m
6. Roadway Width : 7.5 m
7. Width of JGT with 10% overlapping : 5.5 m
8. Cross-section of pavement as per guidelines mentioned in
IRC:SP:72-2007
CBR
ITEMS
WBM – II
WBM – III
GSB – III
GSB-II/Sand
3–4%
5–6%
75mm
75mm
75mm
100mm
75mm
75mm
75mm
50 mm
Jute Geo-Textiles
LOW VOLUME ROAD CONSTRUCTION - ECONOMICS
Rate Analysis of Base Course -
Rates are as per WBSRDA 2012, Murshidabad District. Sub-base layer
consists of well graded material (sand-laterite Gr- II and stone grit &
sand Gr-III)
CONVENTIONAL METHOD (Table 1)
S.No.
DESCRIPTION
OF ITEMS
LENGTH
(m)
WIDTH
(m)
THICKNES
S
(m)
QUANTITY RATE
(m3)
(Rs.)
AMOUNT
(Rs.)
1.
GSB – II
1000
8.8
0.1
880
1300
1144000
2.
GSB – III
1000
4.05
0.075
303.75
2000
607500
3.
Total
1751500
Jute Geo-Textiles
LOW VOLUME ROAD CONSTRUCTION - ECONOMICS
WITH JUTE GEOTEXTILE (JGT) (Table 2)
S.No.
DESCRIPTION
OF ITEMS
LENGTH
(m)
WIDTH
(m)
THICKNES
S
(m)
QUANTITY RATE
(m3)
(Rs.)
AMOUNT
(Rs.)
1.
Coarse Sand
below JGT
Woven JGT
Coarse Sand
above JGT
GSB – III
Total
1000
8.5
0.025
212.5
650
138125
1000
1000
5.5
5.5
0.025
5500
137.5
70
650
385000
89375
1000
4.05
0.075
303.75
2000
607500
1220000
2.
3.
4.
5.
Jute Geo-Textiles
LOW VOLUME ROAD CONSTRUCTION - ECONOMICS
 Procedure For Cost Quantification STEP 1 Quantify Cost of Base Course Material
a) GSB – II : Rs. 1144000/ m3 (Rs. 1.3/ mm thickness/ m2 of
pavement)
b) GSB – III : Rs. 607500/ m3(Rs. 2/ mm thickness/ m2 of
pavement)
c) JGT : Rs. 70/ m2
STEP 2 . Thickness Reduction, ∆tr = 50 mm
STEP 3. Construction Cost savings - CCS/m2
= ∆tr (a+b) – c= Rs. 95/ m2
STEP 4. Construction Cost savings - CCS/ lane – km= 85 x 1000 x 3.75
= Rs. 356250/ lane – km
Jute Geo-Textiles
LOW VOLUME ROAD CONSTRUCTION - ECONOMICS
Base Course Cost Savings % =
=
x 100
Application of JGT in road construction is
economical as there is –
20 % reduction in cost of base course.
16 % reduction in thickness.
Jute Geo-Textiles
JGT in RIVER BANK PROTECTION
Factors driving river bank erosion are
1. Presence of erodible bank soil,
2. Fluctuation in water level, and
3. Development of differential overpressure during drawdown.
Role of JGT in River Bank Protection
1. Ensures better relative density or tightness of bank soil by
retaining soil particles (separation).
2. Permittivity and transmissivity functions of JGT allows water
to pass across without developing uplift pressure.
3. Acts as a catalyst in developing natural graded filter (filter
cake) by interaction with soil bed.
Conventional inverted filter consist of bulk of materials (thick filter
)which belong to different grades and consumes lots of money and time.
 Thick granular inverted filter can be replaced by JGT, thereby
conserving materials, time and money.
Jute Geo-Textiles
RIVER BANK PROTECTION - ECONOMICS
Assumptions for Computation of riverbank construction savings –
1. Total Length of protection work = 1km
2. Length of Slope of protection work = 15 m
3. Thickness of conventional graded inverted filter = 125 mm
4. Quantity of JGT required for total length of protection work =
15000 m2
5. Thickness of riprap/armor (boulders of 30/45 kg) = 300 mm
6. Thickness of JGT = 2 mm
Slope Length = 15m
Jute Geo-Textiles
RIVER BANK PROTECTION - ECONOMICS
The rates are derived from SoR, Eastern Circle, I & W Directorate,
Oct 2009 inclusive of transportation to the site location with 30% hike
in rates as on date are considered.
Type
Filter Layer
a) Graded
inverted filter
125mm thick
b) Jute Geotextiles
c) Boulder 30/45 kg
 300 mm thick
riprap
Quantity
1875 m3
Conventional
Rate
Amount (Rs.)
2020.00
3787500.00
15000 m2
4500 m3
Total
2100.00
With Jute G.T
Rate
Amount (Rs.)
9450000.00
Rs. 13237500.00
≈Rs. 885/m2
82.00
1230000.00
2100.00
9450000.00
Rs.10680000.00
≈Rs. 710/m2
Jute Geo-Textiles
RIVER BANK PROTECTION - ECONOMICS
Construction Cost Savings/m2 (%) =
=
x 100
x 100
Construction Cost Savings/m2 with JGT = 20 %
use of JGT in river bank protection works is
economical as there is –
20% reduction in cost.
Jute Geo-Textiles
JGT in HILL SLOPE MANAGEMENT
Surficial run-off causes due to
1.
2.
Strong winds, and
Impact of Rainfall
JGT controls hill slope erosion by following mechanism
1.
2.
3.
4.
5.
Providing a protective cover to exposed soil surface
Absorbs a large part of kinetic energy of rain drops
Aperture of JGT acts as successive miniature check dams on
slopes
Reduces the velocity of run-off
Provides overland storage.
Jute Geo-Textiles
HILL SLOPE MANAGEMENT - ECONOMICS
Typical cost comparative analysis has been done between different
GTs. for Restoration of Mine spoil – 500 m X 25 m
Type
a)
Quantity
(m2)
12500
b)
Synthetic
GT.
Coir GT.
c)
Jute GT.
12500
Total
With Synthetic GT.
Rate
Amount (Rs.)
80.00
1000000.00
12500
With Coir GT.
Rate
Amount (Rs.)
40.00
500000.00
Rs.
1000000.00
N.B Rates of fabric are as per prevailing market rate
Rs.
500000.00
With Jute GT.
Rate
Amount (Rs.)
25.00
312500.00
Rs. 312500.00
Jute Geo-Textiles
HILL SLOPE MANAGEMENT - ECONOMICS
Percentage Savings of Cost of Different Fabric as compared to
Jute Geotextile (JGT) a) Savings from SGT(%) =
x 100
= 68.75 %
b) Savings from Coir GT (%) =
x 100
= 37.5 %
From above, it can be concluded that use of JGT in hill slope
management is economical as there is –
69% reduction in cost of fabric from SGT
38% reduction in cost of fabric from Coir GT
Jute Geo-Textiles
LIFE CYCLE ANALYSIS OF JUTE
Life Cycle Assessment (LCA) denotes the systematic analysis of
environmental impact of products during their entire life cycle (extraction and
treatment of raw materials, production, distribution and transport, use,
consumption and disposal)
Retting of
jute plant
CO2
assimilation
Jute sticks as
substitute of fire
Pollution
Jute
cultivation
Jute Fibre
Production
Soilenrichment
Residue
Jute Products &
its waste
Biodegradable
material
Jute Geo-Textiles
LIFE CYCLE ANALYSIS OF JUTE
The Life Cycle Analysis of jute products especially mentions the following
(Jan E.G. van Dam and Harriëtte L. Bos, 2006):
Total of 520-1120 kg CO2 emission per ton of jute, while 2.4 ton CO2 is fixed
from the atmosphere by growing jute. A positive balance of 1.3 - 1.9 ton CO2 per
ton of jute fibre produced.
 Life cycle impact (LCI) analysis jute can be classified more environmentally
friendly than PP
Jute
PP
Ratio (PP/Jute)
Waste produced (tons of Waste/tons of product) 0.9
5.5
6.1
Water Consumption per ton of product(m3)
54 to 81
1.3
0.016 to 0.02
Energy Consumption per ton of product (GJ/t)
5.4 to 14.35
84.3
5.9 to 15.6
CO2 emission (tons of CO2/tons of product)
- 1.2 to 0
3.7 to 7.5
Embodied Energy (MJ / kg)
3.75 to 8.02
64 to 84.3
17.06 to 76.28
Jute Geo-Textiles
LOW VOLUME ROAD CONSTRUCTION – ENVIRONMENTAL ASPECTS
Delivering materials to site = Consumes Fuel + Depletion of natural
stones = Carbon emission as well as depletion of non-renewable
resource like diesel and natural stones
a) Quantification of diesel consumption
1.
2.
3.
4.
5.
6.
Diesel consumption depend on various factors like their laden
weight, driving speed, congestion in roads, tire pressure etc.
Considering a truck consumes 6km/l diesel and distance
between quarry site to construction site as 50km.
Capacity of Punjab Body Truck = 14 m3
Volume of saved quantity of 50 mm GSB for 1 km and 8.8 wide
= 440 m3
Number of trips required for carrying 440 m3 of GSB to site =
32
Number of trips required for carrying JGT to site = 1
Jute Geo-Textiles
LOW VOLUME ROAD CONSTRUCTION – ENVIRONMENTAL ASPECTS
Effective savings will be in terms of diesel consumption will be = 31
trips of truck .
 Diesel consumption for 31 passes = 259 litres
JGT will save 259 litres of diesel for 1 km road construction
b) Quantification of natural resources consumption –
less hauling of granular material will result in significant fuel savings
and emissions reduction.
For 50mm reduced thickness with JGT application, quantity of
aggregate conserved = 440 m3 which reduces both costs and use of
scarce resources.
Jute Geo-Textiles
LOW VOLUME ROAD CONSTRUCTION – ENVIRONMENTAL ASPECTS
c) Quantification of vehicular emissions –
Emissions quantified based on number of vehicles and distance
travelled is given by (Gurjar et al., 2004)
Ei =
x Ei,j,km
where, Ei = Emission of compound, Veh = No. of vehicles of each type
D = Distance travelled from quarry to site = 50km
Ei,j,km = emission of compound from vehicle per driven kilometer
= 515.2 gm/km of CO2 from trucks (Mittal and Sharma, 2003)
Ei = 31 x 1 x 50 x 515.2 = 798kg of CO2 is emitted in 31 trips
Carbon Emissions can be reduced by incorporating JGT at the
interface of base course and sub-grade level.
Jute Geo-Textiles
RIVER BANK PROTECTION – ENVIRONMENTAL ASPECTS
a) Quantification of diesel consumption
1.
2.
3.
4.
5.
Considering a truck consumes 6km/lt of diesel and distance to
site location is 50 km.
Volume of saved quantity of 123 mm filter thickness for 1 km
and 15 m wide = 1845 m3
Number of trips required for carrying 1845 m3 of granular
layer to site = 132
JGT transportation will require = 2 trips of truck
Effective savings of 130 trips of truck = Diesel conserved =
1085 litres
JGT will save approx. 1085 lts. of diesel per 1000m of
river bank protection work
Jute Geo-Textiles
RIVER BANK PROTECTION – ENVIRONMENTAL ASPECTS
b) Quantification of natural resources consumption –
For 123 mm reduced thickness with JGT application, quantity of
aggregate/ natural resources conserved = 1845 m3 which reduces
both costs, use of scarce resources and carbon emissions associated
to quarrying.
c) Quantification of vehicular emissions –
Emissions Ei = 130 x 1 x 50 x 515.2 = 3350 kg of CO2 is emitted in 130
trips (that will be conserved using JGT)
Carbon Emissions can be reduced by incorporating JGT at the
interface of bank soil and boulders.
Jute Geo-Textiles
HILL SLOPE MANAGEMENT– ENVIRONMENTAL ASPECTS
1.
Acts as mulch on its degradation
2.
Residue of fibres left in the soil ultimately enhances its hydraulic
conductivity
3.
JGT can absorb water about 5 times its dry weight creating
congenial micro-climate ensuring quick growth of dense vegetation.
4.
Root-system of vegetation ensures soil detachment and imparts
strength to soil body
JGT- natural product-fosters vegetation growth and paves way for
bio-engineering solution to soil erosional problem.
Jute Geo-Textiles
ECO-CONCORDANCE AND SOCIO-ECONOMIC VALUES OF JUTE
a) Purification of air
About 1.2 kg of CO2 is absorbed from atmosphere per every kg of fibre
produced.
b) Bio-efficiency of jute
Usage of jute in place of wood to make paper pulp will reduce cost of
production and cutting down of trees that will help in preserving
ecological balance.
c) Fertility of Land
Dry matter in the form of leaves and roots remain in soil which
enhances soil organic matter and improves nutrient availability in soil.
Thus jute base multiple cropping increases agricultural production.
d) Improvement in Economy
Jute cultivation creates direct employment to farmers, industrial
workers and indirect employment to workers associated with ancillary
industries. Thus helps in economical upliftment of nation.
Jute Geo-Textiles
Thanks for your attention