1286
Proceedings of the 18
th
International Conference on Soil Mechanics and Geotechnical Engineering, Paris 2013
trains (axial load of 30 tons) travelling at 40 km/h were of
magnitude in the order of 0.14-0.17 %.
Table 4. Accumulated longitudinal and transverse strain in geogrid and
geocomposite after 2.3
10
5
load cycles.
Instrumented section details
1
2
3
4
5
l
(%)
0.80
0.78
0.61
0.60
0.62
t
(%)
0.85
1.50
0.80
1.80
0.85
5 CONCLUSIONS AND RECOMMENDATIONS
forcement and shock mats on
ere examined. The results of the Bulli field
the use of geocomposites as reinforcing
ed ballast proved to be a feasible and
stud
rela
lated strains in the
the
mo
futu
loa
The
(ARTC), and QR National for
Ian
sign
and
Ash
Cho
Indr
Indr
Indr
B., Nimbalkar S. and Christie D. 2009. The performance of
Roads,
Indr
2378-2387.
Ind
ference
Indr
nternational Conference of International Association for
nd Improvement
, 10(3), 91-101.
l Engineering
, M. A. Shahin & H. Nikraz
Indr
rack
Journal of Railway Technology
1 (1), 195-219.
nthetic Grids in the
do 2012, 10-
Indr
speeds with heavier freight.
Sixteenth annual Symposium of Australian Geomechanics Society
,
Sydney Chapter, 10 October 2012, Sydney, Australia, 1-24.
Jenkins H. M., Stephenson J. E., Clayton G. A., Morland J. W. and
Lyon D. 1974. The effect of track and vehicle parameters on
wheel/rail vertical dynamic forces.
Railway Engineering Journal
3,
2-16.
Lackenby J., Indraratna B., McDowel G. and Christie D. 2007 Effect of
confining pressure on ballast degradation and deformation under
cyclic triaxial loading.
Géotechnique
57(6), 527-536.
Liu C. N., Ho, Y-H, and Huang J. W. 2009. Large scale direct shear
tests of soil/PET-yarn geogrid interfaces.
Geotextiles and
Geomembranes
, 27, 19-30.
Nimbalkar S., Indraratna B., Dash S. K. and Christie D. 2012 Improved
performance of railway ballast under impact loads using shock
mats.
Journal of Geotechnical and Geoenvironmental Engineering
ASCE 138(3), 281-294.
Raymond G. P. 2002. Reinforced ballast behaviour subjected to
repeated load.
Geotextiles and Geomembranes
20(1), 39-61.
Raymond G. P. and Diyaljee V. A. 1979. Railroad ballast load ranking
classification.
Journal of Geotechnical Engineering
ASCE 105(10),
1133-1153.
Robertson P. K. 1990. Soil classification using the cone penetration test,
Canadian Geotechnical Journal
, 27, 151-158.
Selig E. T. and Waters J. M. 1994.
Track Geotechnology and
Substructure Management
. Thomas Telford, London.
Tang X., Chehab G. R. and Palomino A. 2008. Evaluation of geogrids
in stabilizing weak pavement subgrade.
International Journal of
Pavement Engineering
, 9(6), 413-429.
The effects of geosynthetic rein
the performance of ballasted rail tracks were discussed in this
paper. The use of shock mats was beneficial in terms of reduced
ballast breakage and attenuated impact forces. A few impact
blows were observed to have caused considerable ballast
breakage (
BBI
= 17%). Due to the placement of shock mats,
BBI
could be reduced by approximately 47% over a stiff
subgrade and by approximately 65% over a weak subgrade.
The performance of instrumented ballasted tracks at Bulli
and Singleton was evaluated, in which different types of
geosynthetics w
study indicated that
elements for recycl
economically attractive alternative. The results of the Singleton
y revealed that the effectiveness of geogrids is greater for
tively weak subgrades. The accumu
geogrids were influenced by the subgrade deformation, while
induced transient strains were mainly affected by the
geogrid stiffness. An in-depth understanding of the geogrid and
shock mat stabilised performance would allow for safer and
re effective ballasted track design and construction in the
re, especially for increased trains speeds where high cyclic
ding together with impact is almost inevitable.
6 ACKNOWLEDGEMENTS
authors are grateful to the CRC for Rail Innovation for funding a
significant part of this research. The authors express their sincere
thanks to RailCorp (Sydney), Australian Rail Track Corporation
their continuous support. The
assistance provided by senior technical officers, Mr Alan Grant, Mr
Bridge, and Mr Cameron Neilson is also appreciated. A
ificant part of the contents of this paper are described in a number
cholarly jo
of s
urnals including Géotechnique, and ASCE Journal of
Geotechnical and Geoenvironmental Engineering, as cited in the text
listed below.
7 REFERENCES
mawy A.K. and Bourdeau P.L. 1995. Geosynthetic-reinforced soils
under repeated loading: a review and comparative design study.
Geosynthetics International
2(4), 643-678.
Brown S.F., Kwan J. and Thom N.H. 2007. Identifying the key
parameters that influence geogrid reinforcement of railway ballast.
Geotextiles and Geomembranes
25(6), 326-335.
udhury J. 2006.
Geotechnical investigation report for proposed
bulli track upgrading between 311 & 312 turnouts: dn track
71.660~71.810km, up track 71.700~71.780km
, Memorandum,
Engineering Standards & Services Division, Geotechnical Services,
NSW, Australia
Indraratna B. and Nimbalkar S. 2012. Stress-strain-degradation response
of railway ballast stabilised with geosynthetics.
Journal of
Geotechnical and Geoenvironmental Engineering
ASCE (accepted,
in press).
aratna B. and Salim W. 2003. Deformation and degradation
mechanics of recycled ballast- stabilised with geosynthetics.
Soils
and Foundations
43(4), 35-46.
Indraratna B., Ionescu D. and Christie D. 1998. Shear behaviour of
railway ballast based on large-scale triaxial tests.
Journal of
Geotechnical and Geoenvironmental Engineering
ASCE 124(5),
439-439.
aratna B., Lackenby J. and Christie D. 2005. Effect of confining
pressure on the degradation of ballast under cyclic loading.
Géotechnique
55(4), 325-328.
aratna
rail track incorporating the effects of ballast breakage, confining
pressure and geosynthetic reinforcement.
Proceedings of 8th
International Conference on the Bearing Capacity of
Railways, and Airfields
, London: Taylor and Francis Group, 5-24.
aratna B., Nimbalkar S. and Tennakoon N. 2010b. The behaviour of
ballasted track foundations: track drainage and geosynthetic
reinforcement.
GeoFlorida 2010, ASCE Annual GI Conference
,
February 20-24, 2010, West Palm Beach, Florida, USA,
Indraratna B., Nimbalkar S., Christie D., Rujikiatkamjorn C. and Vinod
J.S. 2010a. Field assessment of the performance of a ballasted rail
track with and without geosynthetics.
Journal of Geotechnical and
Geoenvironmental Engineering
ASCE 136(7), 907-917.
Indraratna B., Nimbalkar S., Rujikiatkamjorn C. and Christie D. 2011b.
State-of-the-art design aspects of ballasted rail tracks incorporating
particle breakage, role of confining pressure and geosynthetic
reinforcement.
Proceedings of 9th World Congress on Railway
Research
WCRR 2011, Lille, France, 1-13.
Indraratna B., Salim W. and Rujikiatkamjorn, C. 2011a
Advanced Rail
Geotechnology – Ballasted Track
CRC Press/Balkema.
raratna B., Shahin M.A. and Salim W. 2007. Stabilising granular
media and formation soil using geosynthetics with special re
to Railway engineering,
Ground Improvement
, 11(1), 27-44.
aratna, B. and Nimbalkar, S. 2011. Implications of Ballast Breakage
on Ballasted Railway Track based on Numerical Modelling,
Proc.
13th I
Computer Methods and Advances in Computational Mechanics
,
IACMAG 2011, Melbourne Australia, May 09-11, 2011, 1085-
1092.
Indraratna, B., Khabbaz, H., Salim, W. and Christie, D. 2006.
Geotechnical properties of ballast and the role of geosynthetics in
rail track stabilization.
Grou
Indraratna, B., Nimbalkar, S. and Rujikiatkamjorn, C. 2011c.
Stabilisation of Ballast and Subgrade with Geosynthetic Grids and
Drains for Rail Infrastructure,
International Conference on
Advances in Geotechnica
(Eds.), November, 7-8, 2011, Perth, Australia, 99-112.
aratna, B., Nimbalkar, S. and Rujikiatkamjorn, C. 2012a. T
Stabilisation with Geosynthetics and Geodrains, and Performance
Verification through Field Monitoring and Numerical Modelling,
International
Indraratna, B., Nimbalkar, S. and Rujikiatkamjorn, C. 2012b.
Performance Evaluation of Shock Mats and Sy
Improvement of Rail Ballast.
Proc. Second International
Conference on Transportation Geotechnics
, IS-Hokkai
12 September 2012, Sapporo, Japan, 47-62.
aratna, B., Nimbalkar, S. and Rujikiatkamjorn, C. 2012c. Future of
Australian rail tracks capturing higher
