Application of Optical-Fiber Bragg Grating Sensors in Monitoring the Rail Track Deformations

S. K. Karimullah Hussaini, 1 Buddhima Indraratna, 2 and Jayan S. Vinod 3

1. Assistant Professor, Department of Civil and Environmental Engineering, Indian Institute of Technology Patna, Bihar-800013, India,
Formerly Ph.D. Candidate at Centre for Geomechanics and Railway Engineering, Univ. of Wollongong,Wollongong City, NSW 2522, Australia.
2. Professor of Civil Engineering and Research Director, Centre for Geomechanics and Railway Engineering; Univ. of Wollongong,Wollongong City, NSW 2522, Australia (Corresponding author)
3. Senior Lecturer in Civil Engineering, Centre for Geomechanics and Railway Engineering, Univ. of Wollongong, Wollongong City, NSW 2522, Australia

Geotechnical Testing Journal, Vol. 38, No. 4, 2015, pp. 387–396

doi:10.1520/GTJ20140123. ISSN 0149-6115


The lateral flow of ballast during the passage of trains can reduce the stability of rail tracks. Therefore, it is important to monitor and restrain the movement of ballast accordingly in order to prevent track misalignment. This current study explored the use of optical-Fiber Bragg Grating (FBG) sensors to measure the lateral displacement of unreinforced and geogrid-reinforced ballast. The tests were conducted on fresh latite basalt at a loading frequency of 20 Hz and up to 250 000 load cycles. The test results showed that the FBG sensing system is fully capable of measuring the lateral displacement of ballast under high frequency cyclic loading. A comparison of strains obtained from FBGs installed at different depths along the ballast depth is made and the lateral strain profiles are measured. Moreover, an empirical model to convert the FBG strains to an equivalent lateral displacement of ballast is proposed to effectively use this technology in real-time monitoring of track deformations.


ballast, cyclic loading, geogrid, FBG sensors, optical fiber, track monitoring, lateral strain profiles


AS 2758.7, 1997: Aggregates and Rock for Engineering Purposes, Part 7: Railway Ballast, Standards Association of Australia, Sydney, Australia.

Atalar, C., Das, B. M., Shin, E. C., and Kim, D. H., 2001, “Settlement of Geogrid Reinforced Railroad Bed Due to Cyclic Load,” Proceedings of 15th International Conference on Soil Mechanics and Geotechnical Engineering, Istanbul, Turkey, Aug 27–31, Taylor & Francis, London, pp. 2045–2048.

Aursudkij, B., McDowell, G. R., and Collop, A. C., 2009, “Cyclic Loading of Railway Ballast Under Triaxial Conditions and in a Railway Test Facility,” Gran. Matter, Vol. 11, No. 6, pp. 391–401.

Baessler, M. and Rucker, W., 2003, “Track Settlement Due to Cyclic Loading With Low Minimum Pressure and Vibrations,” System Dynamics and Long-Term Behaviour of Railway Vehicles, Track and Subgrade, K. Popp and W. Schiehlen, Eds., Springer, Berlin, pp. 337–356.

Chen, C., McDowell, G. R., and Thom, N. H., 2013, “Discrete Element Modelling of Cyclic Loads of Geogrid-Reinforced Ballast Under Confined and Unconfined Conditions,” Geotext. Geomembr., Vol. 35, No. 12, pp. 76–86.

Connolly, C., 2006, “Fibre-Optic-Based Sensors Bring New Capabilities to Structural Monitoring,” Sens. Rev., Vol. 26, No. 3, pp. 236–243.

Dijcker, R., Wijk, M. V. D., Artie`res, O., Dortland, G., and Lostumbo, J., 2011, “Geotextile Enabled Smart Monitoring Solutions for Safe and Effective Management of Tailings and Waste Sites, Two Case Studies: Volgermeerpolder (The Netherlands) and Suncor (Canada),” presented at the Tailings and Mine Waste Conference, Vancouver, BC, Nov 6–9, Norman B. Keevil Institute of Mining Engineering, Vancouver, BC, pp. 1–8.

Esveld, C., 2001, Modern Railway Track, MRT-Productions, Zaltbommel, the Netherlands.

Guo, H., Xiao, G., Mrad, N., and Yao, J., 2011, “Fiber Optic Sensors for Structural Health Monitoring of Air Platforms,” Sensors, Vol. 11, No. 4, pp. 3687–3705.

Ho, Y. T., Huang, A. B., and Lee, J. T., 2006, “Development of a Fibre Bragg Grating Sensored Ground Movement Monitoring System,” Meas. Sci. Technol., Vol. 17, No. 7, pp. 1733–1740.

Hussaini, S. K. K., 2013, “An Experimental Study on the Deformation Behaviour of Geosynthetically Reinforced Ballast,” Ph.D. thesis, University of Wollongong, Wollongong, Australia.

Indraratna, B., Hussaini, S. K. K., and Vinod, J. S., 2012, “On the Shear Behavior of Ballast-Geosynthetic Interfaces,” ASTM Geotech. Test. J., Vol. 35, No. 2, pp. 305–312.

Indraratna, B., Hussaini, S. K. K., and Vinod, J. S., 2013, “The Lateral Displacement Response of Geogrid-Reinforced Ballast Under Cyclic Loading,” Geotext. Geomembr., Vol. 39, pp. 20–29.

Indraratna, B., Nimbalkar, S., Christie, D., Rujikiatkamjorn, C., and Vinod, J. S., 2010, “Field Assessment of the Performance of a Ballasted Rail Track With and Without Geosynthetics,” J. Geotech. Geoenviron. Eng., Vol. 136, No. 7, pp. 907–917.

Indraratna, B., Salim, W., and Rujikiatkamjorn, C., 2011, Advanced Rail Geotechnology-Ballasted Track, CRC Press,

Boca Raton, FL. Indraratna, B., Shahin, M. A., and Salim, M. W., 2005, “Use of Geosynthetics for Stabilising Recycled Ballast in Railway Track Substructures,” presented at the North American Geosynthetics Society (NAGS)-Geosynthetics Institute (GSI) Conference, Las Vegas, NV, Dec 14–16, NAGS, Albany, NY, pp. 1–15.

Ionescu, D., Indraratna, B., and Christie, H. D., 1998, “Behaviour of Railway Ballast Under Dynamic Loads,” Proceedings of the 13th Southeast Asian Geotechnical Conference and the Fourth International Conference on Tropical Soils, Taipei, Taiwan, Nov 16–20, Southeast Asian Geotechnical Society, Taiwan, pp. 69–74. 

Iten, M., 2011, “Novel Applications of Distributed Fiber-OpticSensing in Geotechnical Engineering,” Ph.D. thesis, ETH Zu¨rich, Zurich, Switzerland.

Jeffs, T. and Tew, G. P., 1991, A Review of Track Design Procedures: Sleepers and Ballast, Railways of Australia BHP Research, Melbourne Laboratories, Melbourne, Australia.

Lackenby, J., Indraratna, B., McDowell, G., and Christie, D., 2007, “Effect of Confining Pressure on Ballast Degradation and Deformation Under Cyclic Triaxial Loading,” Geotechnique, Vol. 57, No. 6, pp. 527–536.

Le Pen, L., 2008, “Track Behaviour: The Importance of the Sleeper to Ballast Interface,” Ph.D. thesis, University of Southampton, Southampton, UK.

Le Pen, L. M. and Powrie, W., 2011, “Contribution of Base, Crib and Shoulder Ballast to the Lateral Sliding Resistance of Railway Track: A Geotechnical Perspective,” Proc. Inst. Mech. Eng. Part F, Vol. 225, No. 2, pp. 113–128.

Lee, W., Lee, W. J., Lee, S. B., and Salgado, R., 2004a, “Measurement of Pile Load Transfer Using the Fiber Bragg Grating Sensor System,” Can. Geotech. J., Vol. 41, No. 6, pp. 1222–1232.

Lee, K. Y., Lee, K. K., and Ho, S. L., 2004b, “Exploration of Using FBG Sensor for Axle Counter in Railway Engineering,” WSEAS Trans. Syst., Vol. 6, No. 3, pp. 2440–2447.

Liehr, S., Lenke, P., Krebber, K., Seeger, M., Thiele, E., Metschies, H., Gebreselassie, B., Mu¨nich, J. C., and Stempniewski, L., 2008, “Distributed Strain Measurement With Polymer Optical Fibers Integrated Into Multifunctional Geotextiles,” Proc. SPIE, Vol. 7003, 700302.

Mamidi, V. R., Kamineni, S., Ravinuthala, L. N. S. P., Madhuvarasu, S. S., Thumu, V. R., Pachava, V. R., and Putha, K., 2014, “Fiber Bragg Grating-Based High Temperature Sensor and its Low Cost Interrogation System With Enhanced Resolution,” Opt. Appl., Vol. 44, No. 2, pp. 299–308.

Measures, R. M., 2001, Structural Monitoring With Fiber Optic Technology, Academic Press, New York.

Micron Optics, Inc., 2007, “Si 425: Optical Sensing Interrogator Instruction Manual,” Atlanta, USA.

Mihailov, S. J., 2012, “Fiber Bragg Grating Sensors for Harsh Environments,” Sensors (Basel), Vol. 12, No. 2, pp. 1898–1918.

No¨ther, N., Glo¨tzl, R., Vollmert, L., Ehrenberg, H., Weisemann, U., Großmann, S., and Oehmichen, R., 2012, “Displacement Monitoring in Geotechnical Applications Using Optical Fiber Sensors in Geosynthetics,” presented at the 6th European Workshop on Structural Health Monitoring, Dresden, Germany, July 2–6, German Society for Nondestructive Testing, Berlin, pp. 1–7.

Raymond, G. P. and Bathurst, R. J., 1994, “Repeated-Load Response of Aggregates in Relation to Track Quality Index,” Can. Geotech. J., Vol. 31, No. 4, pp. 547–554.

Rowe, R. K. and Gnanendran, C. T., 1994, “Geotextile Strain in a Full Scale Reinforced Test Embankment,” Geotext. Geomembr., Vol. 13, No. 12, pp. 781–806.

Selig, E. T. and Waters, J. M., 1994, Track Geotechnology and Substructure Management, Thomas Telford Services Ltd., London.

Schmidt-Hattenberger, C., Straub, T., Naumann, M., Borm, G., Lauerer, R., Beck, C., and Schwarz, W., 2003, “Strain Measurements by Fiber Bragg Grating Sensors for In-Situ Pile Loading Tests,” Proc. SPIE, Vol. 5050, pp. 289–294.

Weng, X. and Wang, W., 2011, “Influence of Differential Settlement on Pavement Structure of Widened Roads Based on Large-Scale Model Test,” J. Rock Mech. Geotech. Eng., Vol. 3, No. 1, pp. 90–96.

Xu, D. S., Yin, J. H., Cui, P., Pei, H. F., Zhu, H. H., and Hong, C. Y., 2011, “Monitoring and Analysis of Internal Displacements of a Slope and Relationship With Rainfall Infiltration,” Proceedings of 3rd International Postgraduate Conference on Infrastructure and Environment, Hong Kong, July 12–14, S. J. Liu, Ed., The Hong Kong Polytechnic University, Hong Kong, pp. 117–123.

Yoon, H.-J., Song, K.-Y., Kim, J.-S., and Kim, D.-S., 2011, “Longitudinal Strain Monitoring of Rail Using a Distributed Fiber Sensor Based on Brillouin Optical Correlation Domain Analysis,” NDT&E Int., Vol. 44, No. 7, pp. 637–644.

Zhu, H., 2009, “Fiber Optic Monitoring and Performance Evaluation of Geotechnical Structures,” Ph.D. thesis, The Hong Kong Polytechnic University, Hong Kong.