LOAD SETTLEMENT BEHAVIOUR OF JUTE GEOTEXTILE
REINFORCED SUBGRADE OF RURAL ROAD USING ABAQUS
Sudip K. Roy
Ambarish Ghosh
Ashis Kumar Bera
Sandip Chakraborty
Department of Civil Engineering

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•

•
Researchers
S. Pirabarooban, M. Zaman,
R. A. Tarefder. (2003)
K. Nesnas, M. Nunn. (2004)
R. Zafar, W. Nassar and A.
Elbella. (2005)
W.G. Buttlar, G. H. Paulino, and S. H.Song. (2006)
Research Area/ Findings
FEM results show that the ABAQUS-based model can adequately account for cyclic loading and other factors and, as such, it can be used effectively to evaluate the rutting potential of in-service pavement.
A response model (3D) is generated in ABAQUS to predict top down cracking
In this study the finite element software ABAQUS is used to study stress redistribution due to the presence of earth pressure cell (vertical stress-measuring instrument) in the pavement layers
Numerical examples and an implementation using the user material subroutine UMAT of the finite element software ABAQUS are also provided to illustrate the benefits of using graded elements in pavement analysis.

•
Researchers
Tabakovic, Amir; McNally,
Ciaran; Sorelli, L. G.; Gibney,
Amanda; Gilchrist, M.
D.
(2006)
Grace G. Abou-Jaoude, Ziad
G. Ghauch
A.M.Khaki, E. Azadravesh.
(2010)
Rahman M.T , Mahmud K,
Ahsan S. (2011)
Research Area/ Findings
A damage mechanics model has been developed in order to compare the behaviour of RAP (Recycled
Asphalt Pavement), The damage model was implemented within the ABAQUS finite element code using a UMAT subroutine
A 3D Finite Element model of the pavement involving a linear viscoelastic constitutive model for HMA materials and non-uniform tire contact stresses is developed using
ABAQUS 6.11 to investigate the effectiveness of several design strategies involved in long-life, perpetual pavement design
A 3D FE model is generated by ABAQUS for evaluating the effects of joint opening on load transfer efficiency in concrete pavements
In this study, a 3D finite element model of flexible pavement is developed using ABAQUS for better prediction of mechanical behaviour and pavement performance subjected to various traffic factors.

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Researchers
B. Sukumaran, V. Kyatham,
A. Shah, D.Sheth. (2004)
Gholam Ali Shafabakhsh,
Abbas Akbari. (2013)
Gholam Ali Shafabakhsh,
Mana Motamedi, Afshin
Family. (2013)
Research Area/Findings
The stress-strain response of the various soils is simulated using an elasto-plastic model and von Mises strength criteria available in finite element code
ABAQUS. The empirical relationship between CBR and resilient modulus is investigated based on the results obtained from the three dimensional finite element analyses.
3D modelling with help of finite element computer code
ABAQUS has been used to determine the role of different parameters of passenger, commercial and military airplane’s main gear s which cause the major failures to the rigid runway pavements.
This research, at first, tends to investigate influence of changing asphalt pavement thickness in vertical strain using finite element software (ABAQUS) and finally, the results related to the finite element, were compared with experimental data.


A Finite element Software

Robustness in numerical solution strategy for soil nonlinearity,

Capable of solving most geotechnical problems,

Involving two- and three-dimensional configurations,
 Soil and structural elements,
 Wide range of material property can be used

Total and effective stress analysis,

Consolidation analysis,

S eepage analysis,

Static and dynamic analysis, etc.



 Kuo and Chou (2004) developed and analyzed a three dimensional model for flexible pavement using ABAQUS software

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Bera et al. ( 2009 ) carried out series of unconfined compression strength tests of fly ash reinforced with jute geotextile.
•
Chattopadhyay and Chakraborty ( 2009 ) studied the application of
JGT as facilitator in drainage.
•
Sahu et al. ( 2004 ) carried out model footing test to determine the behaviour of JGT reinforced soil bed and to asses aging effect of soil along with degradation of JGT with time

Rajar hat Test Track
• A trial stretch road section:
• Data Given:
• CBR=3% (assumed)
• ESAL=60000 to 100000
• Unreinforced Road Section
• As per IRC: SP: 72-2007, Subgrade Strength as per CBR=3%; it is Poor.
• Premix Carpet = 20 mm
• WBM (Grade-II) = 75 mm
• WBM (Grade-III) = 100 mm
• GSB(Grade-II)
=
150 mm
Fig.1 Unreinforced Road Section

Rajar hat Test Track
Fig.2 Unreinforced Road Section ( Reduced GSB )

Rajar hat Test Track
Fig 3.Reinforced Road Section with JGT (20kN/m)

Rajar hat Test Track
Fig 4.Reinforced Road Section JGT (25kN/m)

Rajar hat Test Track
Fig 5.Reinforced Road Section with Geosynthetics

Problem Description
•
Unreinforced Road Section ( Reduced GSB )
•
Reinforced Road Section with JGT (20kN/m)

Geometry of the Model
UR GSB 100 )

Geometry of the Model
UR GSB 175 )

Geometry of the Model
GSB 100 )

Material property
Material Model used
Density
(kN/m 3 )
Elastic
Modulus
(MPa)
19
Poisson’s ratio
0.4
Friction angle
(Degree)
NA
Dilation angle
NA
Cohesion
(kPa)
NA WBM
GSB
Sand
JGT
Linear
Elastic
Linear
Elastic
Linear
Elastic
Linear
Elastic
Subgrade Mohr-
Coulomb model
Existing soil layer
Mohr-
Coulomb model
15.2
14.5
15.5
13.95
14.0
20
15
80
10
12
0.4
0.3
0.3
0.4
0.4
NA
NA
NA
2
10
NA
NA
NA
0
0
NA
NA
NA
30
20

Static Load & Boundary Condition
LOAD
Fig. 9 Load and Boundary condition applied to the model (Reinforced section, JGT100)

Cyclic load and Time Stepping
LOAD

INTERACTION

Meshing Criteria
( a ) UR GSB 100
( b )REINFORCED
Fig.10 Mesh model

Deformed Shape
Results and Discussions
Fig.11 Deformed shape for UR GSB 100

Deformed Shape
Results and Discussions
Fig.12Deformed shape for UR GSB 175

Deformed Shape
Results and Discussions
Fig.13 Deformed shape for JGT Reinforced Section

Deformed Shape
Results and Discussions
JGT
Fig.14 Deformed shape for JGT Reinforced Section

Deformed Shape
Results and Discussions
Fig.15 Deformed and Undeformed shape for JGT Reinforced Section

Results and Discussions
Fig.16 Tensile stress ( ) & Compressive stress ( )

Results and Discussions
0,8
0,7
0,6
0,5
0,4
0,3
0,2
0,1
0
0 5 10 15
Settlement (mm)
20 25 30
Fig.17 Typical Load settlement plot at subgrade unreinforced ( UR GSB 100 ) road section ( by using cyclic loading)

Results and Discussions
0,8
0,7
0,6
0,5
0,4
0,3
0,2
0,1
0
0
JGT
5 10 15
Settlement (mm)
20 25 30
Fig.18 Typical Load settlement plot at subgrade Reinforced road section ( Cyclic loading )

Results and Discussions
Effect of JGT on rut depth of road section
40
50
60
0
10
20
30
0
Load ( MPa )
0,5 1
UR GSB 100
UR GSB 175
JGT+Sand
Fig.19Load (Static) vs. Rut depth (mm)

Results and Discussions
Effect of JGT on rut depth of road section
55,76316
41,03123
34,48359
UR GSB 100 UR GSB 175 JGT+Sand
Fig.20 Rut depth (mm) for the three models ( Subgrade top )

Results and Discussions
Effect of JGT on rut depth of road section
133.3 mm
116.78 mm
Fig.21 Comparison between rut depth for unreinforced ( URGSB 100 ) and reinforced model after 8 hours vehicle movement at an interval of 45 second

Results and discussions
Effect of JGT on stresses developed of Subgrade top

Conclusions
• With the introduction of JGT reinforcement in between subgrade and granular base layer the values of rut depth decreases significantly.
• Cyclic loading developed larger rut depth compared to static loading irrespective of types of road section.
• Stress developed on the subgrade top in case of JGT reinforced road section is much lesser than road section without reinforcement.
• ABAQUS software can effectively analyse the any types of road sections ( Reinforced & Unreinforced ). By using this software researcher may observe any types of load ( compressive/ tensile ), directions, deformations at any point.

References
•
Bera, A.K., Chandra, S.N., and Ghosh, A. ( 2009 ) “ Unconfined compressive strength of fly ash reinforced with jute geotextiles”, Geotextiles and Geomembranes, 27 ( 5 ), pp. 391-398.
•
Bhasi.A. Rajagopal, K.(2010) “Finite Element Analysis of Geosynthetic reinforced pile supported embankments.” SIMULIA Customer Conference.
•
Chattopadhyay, B.C., and Chakraborty, S. ( 2009 ) “ Application of jute geotextiles as facilitator in drainage”, Geotextiles and Geomembranes, 27 ( 2 ), pp. 156-161.
•
Hadi,N.S. and Mukammad. Bodhinayake, B.C. (2003) “Non-linear finite element analysis of flexible pavements” Elsevier, Advances in Engineering Software , 34, pp.657–662.
•
Helwany, S. Dyer, J. and Leidy, J. (1998) “Finite element analysis of flexible pavement.” , Journal of transportation engineering, September/October, pp.491- 499.
•
Helwany,S.(2007) “Applied soil mechanics with Abaqus application”, John Wiley & Sons.
•
Kuo, C.M, Chou, F.J. (2004). “Development of 3-D Finite Element model for Flexible Pavements”
Journal of the Chinese Institute of Engineers, 27, ( 5 ), 707-717.
•
Sahu, R.B., Hazra, A.K.and Som, N. ( 2004 ) “ Behaviour of geojute reinforced soil bed under repetitive loading- a model study” BCC iInternational Conference on Geosynthetics and Geoenvironment
Engineering, Bombay