FEDERATION OF INDIAN CHAMBERS OF
COMMERCE AND INDUSTRY
A Presentation
On
Geo Textiles : Perspective
from the Construction Sector
By
D C DE
CONSULTING ENGINEERING SERVICES (INDIA) PRIVATE LIMITED
19 November 2010
Reinforcement
Geo Drains
Geo Separations
Geotextile Applications in Roads
MSE
ASTM D4439 defined a geotextile as follows
Geotextile : A permeable geosynthetic comprised
solely of textiles. Geotextiles are used with
foundation, soil, rock, earth, or any other
geotechnical engineering-related material as an
integral part of a human-made product structure,
or system.
Due to the very wide range of applications and the
tremendous variety of available textiles having
widely different properties, the selection of a
particular design method or design philosophy is
a critical decision that must be made before the
actual mechanics of the design process are
initiated.
Geotextile Functions and Mechanisms
An overview of geotextiles, alluded to many
applications falling into categories:
 Separation
 Reinforcement
 Filtration
 Drainage
 Containment
When properly identified, lead to the design-byfunction method.
Geotextile choices as available
1. Lightweight Wovens
2. Heavyweight
Wovens
3. High Flow Wovens
4. High Strength
Wovens
5. Thermally Bonded
Non-wovens
6. Needle punched Nonwovens
Geotextile Functions and Mechanisms
Separation
Designed
Thickness
Bituminious
Courses
Aggregate
Bases
Geotextile
Layer
Subgrade
Geotextile Functions and Mechanisms
Filtration and Drainage
Bituminious Courses
Aggregate Bases
Geotextile Layer
Aggregate Drainage
Layer
Subgrade
Geotextile Functions and Mechanisms
Reinforcement
This is the synergistic improvement in the total
system strength created by the introduction of a
geotextile into a soil and developed primarily
through the following three mechanisms:
One, lateral restraint through interfacial friction
between geotextile and soil/aggregate.
Two, forcing the potential bearing surface failure
plane to develop at alternate higher shear strength
surface.
And three, membrane type of support of the wheel
loads.
Geotextile Functions and Mechanisms
Pavement Crack
with Paving Fabric
Sealing Function
New Overlay
Reflective Crack
without Paving Fabric
Old Pavement
Base Course
Major Applications of Geotextiles
Separation of Dissimilar Materials
 Between subgrade and stone base in paved roads
and airfields
 Between landfills and stone base courses
 Between geomembranes and soil drainage layers
 Between foundation and embankment soils for
surcharge loads
 Between foundation and embankment soils for
roadway fills
 Between foundation and encapsulated soil layers
 Between foundation soils and rigid retaining walls
 Between slopes and downstream stability berms
 Beneath precast blocks and panels for aesthetic
paving e.g. hardscaping
Major Applications of Geotextiles
Separation of Dissimilar materials
 Between drainage layers in poorly graded filter
blankets
 Between old and new asphalt layers
Reinforcement of Weak Soils and Other Materials
 To reinforce embankments
 To aid in construction of steep slopes
 As basal reinforcement over soft soils
 To bridge over cracked or jointed rock
 To create more stable side slopes due to high
frictional resistance
Major Applications of Geotextiles
Filtration (Cross-Plane Flow)
 Beneath stone base for paved roads and airfields
 Around crushed stone surrounding under drains
 Around perforated under drain pipe
 As a flexible form for restoring scoured bridge
pier bearing capacity
 Between backfill soil and weep holes in retaining
walls
 Between backfill soil and gabions
 As a filter beneath precast blocks
Major Applications of Geotextiles
Drainage (In-Plane Flow)
 As a drain behind a retaining wall
 As a drain at the base of retaining wall
 As a replacement for sand or wick drains
Band Drains / Prefabricated Vertical Drains (PVD)
These are geocomposites formed of a hollow cored,
geotextile wrapped drainage element (geonet) inserted
vertically into soft ground to speed up the
consolidation process.
Prefabricated Vertical Drain
Installation of PVD
Band Drains / Prefabricated Vertical Drains (PVD)
Kandla Port – Ground improvement
Band drains has been adopted to increase the bearing
capacity of the site. The following parameters have
been adopted:
Scheme
SBC
Spacing of
Preload Duration
before
Band Drain
Height
(Days)
treatment with Triangular
(m)
(T/m2)
Grid
(m)
SBC after
treatment
(T/m2)
Scheme-1
2.00
1.25
4.00
80
10.21
Scheme-2
2.00
1.50
4.00
120
10.11
Band Drains / Prefabricated Vertical Drains (PVD)
at Kolkata
Emerging Issues
R&D Needs of the Indian Geotechnical Industry
The Need to Encourage the Domestic Synthetic
Manufacturing Industry
Need for Establishing a Geosynthetic Institute in
India
Standardization in the Field of Geosynthetics
Geosynthetics Test Standards and Specifications