Transcript JGT Presentation by Prof. Ambarish Ghosh, BESUS

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
Bengal Engineering and Science University, Shibpur
Howrah – 711103 June, 2013
• Why Numerical Analysis?
• SELECTION OF NUMERICAL TOOL
• LITERATURE REVIEW
Researchers
Research Area/ Findings
S. Pirabarooban, M. Zaman,
R. A. Tarefder. (2003)
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.
K. Nesnas, M. Nunn. (2004)
A response model (3D) is generated in ABAQUS to
predict top down cracking
R. Zafar, W. Nassar and A.
Elbella. (2005)
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
W.G. Buttlar, G. H. Paulino,
and S. H.Song. (2006)
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.
• LITERATURE REVIEW
Researchers
Research Area/ Findings
Tabakovic, Amir; McNally,
Ciaran; Sorelli, L. G.; Gibney,
Amanda; Gilchrist, M. D.
(2006)
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
Grace G. Abou-Jaoude, Ziad
G. Ghauch
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.M.Khaki, E. Azadravesh.
(2010)
A 3D FE model is generated by ABAQUS for evaluating
the effects of joint opening on load transfer efficiency in
concrete pavements
Rahman M.T , Mahmud K,
Ahsan S. (2011)
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.
• LITERATURE REVIEW
Researchers
Research Area/Findings
B. Sukumaran, V. Kyatham,
A. Shah, D.Sheth. (2004)
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.
Gholam Ali Shafabakhsh,
Abbas Akbari. (2013)
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.
Gholam Ali Shafabakhsh,
Mana Motamedi, Afshin
Family. (2013)
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.
ABAQUS
 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,
 Seepage analysis,
 Static and dynamic analysis, etc.
ABAQUS
 Huang et al. (2006) carried out finite element analysis to
study the consolidation behaviour of an embankment on soft
ground.
 Hadi and Bodhinayake (2003) carried out finite element
analysis of road emabankment in ABAQUS.
 Kuo and Chou (2004) developed and analyzed a three dimensional
model for flexible pavement using ABAQUS software
Jute Geotextile Application
• 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
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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
• Unreinforced Road Section ( Reduced GSB )
• Reinforced Road Section with JGT (20kN/m)
Geometry of the Model
Fig.6 Unreinforced road section (UR GSB 100 )
Geometry of the Model
Fig.7Unreinforced road section (UR GSB 175 )
Geometry of the Model
Fig.8 JGT ( 20kN/M ) Reinforced road section (GSB 100 )
Material property
Material
WBM
Model
used
Linear
Elastic
GSB
Linear
Elastic
Sand
Linear
Elastic
JGT
Linear
Elastic
Subgrade MohrCoulomb
model
Existing Mohrsoil layer Coulomb
model
Dilation
angle
Cohesion
(kPa)
15.2
Elastic
Poisson’s Friction
Modulus ratio
angle
(MPa)
(Degree)
19
0.4
NA
NA
NA
14.5
20
0.4
NA
NA
NA
15.5
15
0.3
NA
NA
NA
80
0.3
NA
NA
NA
13.95
10
0.4
2
0
30
14.0
12
0.4
10
0
20
Density
(kN/m3)
LOAD
Static Load & Boundary Condition
Fig. 9 Load and Boundary condition applied to the model (Reinforced section, JGT100)
LOAD
Cyclic load and Time Stepping
INTERACTION
Meshing Criteria
( a ) UR GSB 100
( b )REINFORCED
Fig.10 Mesh model
Results and Discussions
Deformed Shape
Fig.11 Deformed shape for UR GSB 100
Results and Discussions
Deformed Shape
Fig.12Deformed shape for UR GSB 175
Results and Discussions
Deformed Shape
Fig.13 Deformed shape for JGT Reinforced Section
Results and Discussions
Deformed Shape
JGT
Fig.14 Deformed shape for JGT Reinforced Section
Results and Discussions
Deformed Shape
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
Load (MPa)
0.6
0.5
0.4
0.3
0.2
0.1
0
0
5
10
15
20
25
30
Settlement (mm)
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
Load (MPa)
0.6
0.5
0.4
0.3
JGT
0.2
0.1
0
0
5
10
15
20
25
30
Settlement (mm)
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
0
Load ( MPa )
0.5
1
Rut depth ( mm )
0
10
UR GSB 100
20
UR GSB 175
30
JGT+Sand
40
50
60
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
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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
Thank You