Prepared by Students of Northern University Bangladesh Golam Rabby (30190300568) Suboara Rahman Piya (30190300575) Jamilur Rahman Efaz (30190300566)

1. WELCOME TO OUR
PRESENTATION

2. PRESENTATION TOPIC:
GEOTEXTILE FOR SOIL
STABILIZATION
NORTHERNUNIVERSITYBANGLADESH
Created by :
Jamilur Rahman Efaz (30190300566)
Golam Rabbi (30190300568)
Suboara Rahman Piya (30190300575)

3.  Soil stabilization is an integral part to any roadway,
railway, or load bearing construction project, as poor
drainage and co-mingling of materials can lead to
rapid structural disintegration and subsequent project
failure. Geotextiles are rapidly becoming the key
component to this dilemma, as their use allows roads
and other load bearing projects to be designed and
installed in much the same manner as before, with the
exception being that far less aggregate is required in
order to accomplish the desired results.

4.  Examples include aggregate over soil and good soil
over poor soil, both of which are common occurrences
in roadway and railway construction. They can help in
a multitude of soil stabilization situations, as they
perform many different tasks, including, but not
limited to:
1. Non-permanent roadways, as geotextile fabrics can
be perfect for applications such as haul roads that only
need to be used for a season or two.

5. 
Fig 1 : Plantico

6.  2. Reinforcing the soil below the geotextile fabric so as
to enable it to be able to carry high tensile loads
without collapsing or spreading. This is one of the key
factors in how geotextiles can extend roadway and
railway lifespan.

7.  They are permeable fabrics which, when used in
association with soil, have the ability to separate, filter,
reinforce, protect, or drain.
Typically made from polypropylene or polyester, geotextile
fabrics come in three basic forms: woven (resembling mail
bag sacking), needle punched (resembling felt), or heat
bonded (resembling ironed felt).
Geotextile composites have been introduced and products
such as geogrids and meshes have been developed. Overall,
these materials are referred to as geosynthetics and each
configuration—geonets, geosynthetic clay liners, geogrids,
geotextile tubes, and others.

8. 
Fig 2: Uses of Geotextile in various places

10. Geotextiles are made up of polymers such as polyester or
polypropylene. They are divided into 3 categories on the
basis of the way they are prepared;
1.Woven Fabric Geotextile :
Commonly found geotextiles are of the woven type and
are manufactured by adopting the techniques which are
similar to weaving usual clothing textiles.

11. 
Fig 3: Woven Geotextile.

12.  2.Non-Woven Geotextile: Non-woven geotextiles are
manufactured from either continuous filament yarn or
short staple fiber. The bonding of fibers is done using
thermal, chemical or mechanical techniques or a
combination of techniques.
Fig 4: Non-Woven Geotextile.

13.  3. Knitted Geotextile: Knitted geotextiles are
manufactured by the process of interlocking a series of
loops of yarn together.
Fig 5: Knitted Geotextile

14.  The mode of operation of a geotextile in any
application is defined by six discrete functions:
Fig 6: Geogrid functions

15.  1 Separation :
The separation function of geotextile is majorly used in the
construction of roads. Geotextile prevents the intermixing
of two adjacent soils. For example, by separating fine sub
grade soil from the aggregates of the base course, the
geotextile preserves the drainage and the strength
characteristics of the aggregate material. Some of the
applicable areas are:
Between sub grade and stone base in unpaved and paved
roads and airfields.
Between sub grade in railroads.
Between landfills and stone base courses.
Between geo membranes and sand drainage layers.

16. 
Fig 7 : Separation

17.  2. Filtration: The equilibrium of geotextile-to-soil
system that allows for adequate liquid flow with
limited soil loss across the plane of the geotextile
3. Reinforcement: Introduction of geotextile in the
soil increases the tensile strength of the soil the same
amount steel does in concrete. The strength gain in
soil due to the introduction of geotextile is by the
following 3 mechanisms:
Lateral restraint through interfacial friction between
geotextile and soil/aggregate.
Forcing the potential bearing surface failure plane to
develop an alternate higher shear strength surface.
Membrane type of support of the wheel loads.

18.  The results of the analysis of geotechnical parameters
of the soil samples are presented and subsequently
discussed and for ease of discussion, the results are
presented as graphical plots and tables.
1. Soil Classification and Sub-Grade Rating: Figure
below shows the sample graph of particle size
distribution for the virgin soils and AASHTO sub grade
rating for this type of soil is ‘poor’.

19.  2. Atterbergs Limit Test : The Atterberg limits are a
basic measure of the critical water contents of a
finegrained soil: its shrinkage limit, plastic limit, and
liquid limit. Liquid limit and plastic limit of the soil
sample is tested to determine its engineering
properties. They had noted that liquid limit less than
35% indicates low plasticity, between 35% and 50%
indicates intermediate plasticity, between 50% and
70% high plasticity, between 70% and 90% very high
plasticity and greater than 90% extremely high
plasticity.

21.  3. Moisture Content: In the various sectors, we most often
define moisture content on a dry basis. This means that the
moisture content is defined as
𝑊𝑒𝑖𝑔ℎ𝑡 𝑜𝑓 𝑤𝑎𝑡𝑒𝑟 ∗ 100%
𝑤𝑒𝑖𝑔ℎ𝑡 𝑜𝑓 𝑠𝑎𝑚𝑝𝑙𝑒
The weight of the sample does not include any water. It is
the weight of the sample after it is oven-dry and all water
has been removed. The weight of the water is the difference
in the weight of the sample before and after drying .The
implication of high moisture content is that the soil might
exhibit a reduced strength.

22.  4. Specific Gravity: The values of specific gravity for
lateritic soil is 2.50 – 2.75 and clay soil is (2.60 –
2.90).This is considered to be acceptably high because
it is required that soils to be used for construction
should have specific gravity that is not less than 2.25
and the mineral composition of the crystalline rock
might have contributed to the relatively high specific
gravity values.

24.  5. California Bearing Ratio Test (CBR):
The CBR is a semi empirical test that is often employed in
the estimation of the bearing capacity of sub grade soils for
design of pavement. It measures the resistance a soil mass
offers to the penetration of a plunger under specified
density and moisture conditions. Sample results of
unsoaked CBR with and without the reinforcement are
presented below. There was a considerable increase in the
CBR values after the inclusion of the non-woven geotextiles
than the CBR values before the inclusion of the non-woven
geotextiles. It can be clearly seen that due to the placement
of non-woven geotextile, the CBR values increases
irrespective of the placement depth.

26. 
Fig 11: CBR values for reinforced and unreinforced soil
sample

30.  This test was performed to establish the relationship
between the Optimum Moisture Content (O.M.C) and
Maximum Dry Density (M.D.D) of the soils for a
specified compactive effort and the maximum amount
of water needed to enhance the strength or load-
carrying capacity of the soil. Dry density values –
moisture content relationship sample curves for the
virgin soil is presented below.

32. 
Fig 16: Dry density – Moisture content relationship of
the soil samples

33. 
Fig 18 : Compaction Test

34.  The principle of building roadways as for other civil
engineering structures is to determine the stresses caused
by a vehicle and compare them with the parameters limit
values of the various constituent materials of the structure.
This level of stress is evaluated by a mechanical model of
the pavement. The latter that researchers are trying to
develop it to make it more representative of physical reality.
Geotextiles are very important part of pavement
construction regarding its strength, durability, and
working performance. They are Very useful in case of silt
and clay. According to California Bearing Ratio (CBR) Test,

35.  it was observed that when the two soil samples were
reinforced with non-woven geotextile, there was an
increase in their CBR values in unsoaked condition
than when compared with their CBR values without
reinforcement which indicate that the soil samples
reinforced with non-woven geotextile are suitable for
sub grade as set by the Federal Ministry of Works
General Specification (1997) criteria for sub grade
soils.

36.  Geotextile reinforced soils present better performance
than traditional soil under dynamic loadings. It is non-
biodegradable, durable and also increases the ultimate
service life of the pavement. It should, therefore be
used to enhance the performance of a sub grade
material in a pavement system.

37. THANK YOU