• Hisham Mohamad Civil and Environmental Engineering Department, Universiti Teknologi PETRONAS, 32610 Seri Iskandar, Perak.
  • Bun Pin Tee Faculty of Civil Engineering, Universiti Teknologi Malaysia, 81310 UTM Johor Bahru, Johor, Malaysia
  • Koh An Ang GDS Instruments Sdn. Bhd., 40400 Shah Alam, Selangor, Malaysia
  • Mun Fai Chong Dynamic Pile Testing Sdn. Bhd., 40150 Shah Alam, Selangor, Malaysia



Bored pile, fiber-optic sensing, BOTDA, maintained load test


This paper describes the method of identifying typical defects of bored cast-in-situ piles when instrumenting using Distributed Optical Fiber Strain Sensing (DOFSS). The DOFSS technology is based on Brillouin Optical Time Domain Analyses (BOTDA), which has the advantage of recording continuous strain profile as opposed to the conventional discrete based sensors such as Vibrating Wire strain gauges. In pile instrumentation particularly, obtaining distributed strain profile is important when analysing the load-transfer and shaft friction of a pile, as well as detecting any anomalies in the strain regime. Features such as defective pile shaft necking, discontinuity of concrete, intrusion of foreign matter and improper toe formation due to contamination of concrete at base with soil particles, among others, may cause the pile to fail. In this study, a new technique of detecting such defects is proposed using DOFSS technology which can potentially supplement the existing non-destructive test (NDT) methods. Discussion on the performance of instrumented piles by means of maintained load test are also presented


Bica, A.V.D., Prezzi, M., Seo, H., Salgado, R., and Kim, D. 2014. Instrumentation and Axial Load Testing of Displacement Piles. Proc. ICE, Geotech. Engng. 167(3): 238 – 252.

Hajduk, E.L., and Paikowsky S.G. 2000. Performance Evaluation of An Instrumented Test Pile Cluster. Proceedings of ASCE Specialty Conference, Performance Verification of Constructed Geotechnical Facilities, Amherst, MA, USA (Lutenegger AJ and DeGroot DJ (eds)). ASCE, Reston, VA, USA, ASCE Geotechnical Special Publication. 94: 124–147.

Mohamad, H., Soga K., Pellew, A., and Bennett, P.J. 2011. Performance Monitoring of a Secant Piled Wall using Distributed Fiber Optic Strain Sensing. Journal of Geotechnical and Geoenvironmental Engineering. 137(12):1236-1243.

Mohamad, H., Bennett, P. J., Soga K., Mair, R. J., and Bowers, K. 2010. Behaviour of an Old Mansonry Tunnel due to Tunnelling Induced Ground Settlement. Géotechnique. 60(12):927–938.

Nellen, Ph. M., Bronnimann, R., Frank, A., Mauron, P. and Sennhauser, U., 1999. Structurally Embedded Fiber Bragg Gratings: Civil Engineering Applications. Proc. SPIE Fiber Optic Sensor Technology and Applications. 3860: 44.

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. Proceedings of SPIE - The International Society for Optical Engineering. 5050: 289-294.

Oh, J. H., Lee, W. J., Lee, S. B., and Lee, W. J. 2000. Analysis of Pile Load Transfer using Optical Fiber Sensor. In Proceedings of SPIE - The International Society for Optical Engineering. Society of Photo-Optical Instrumentation Engineers. 3988: 349-358.

Kister, G., Winter, D., Gebremichael, Y. M., Badcock, R. A., Tester, P. D., Krishnamurthy, S., Boyle, W. J. O., Grattan, K. T. V., and Fernando, G. F. 2007. Methodology and Integrity Monitoring of Foundation Concrete Piles using Bragg Grating Optical Fibre Sensors. Engineering Structures. 29(9): 2048–2055.

Mohamad, H., and Tee, B.P. 2015. Instrumented Pile Load Testing with Distributed Optical Fibre Strain Sensor. Jurnal Teknologi (Sciences & Engineering). 77(11): 1–7.

Mohamad, H., Soga, K., and Bennett, P.J. 2009. Fibre Optic Installation Techniques for Pile Instrumentation. Proceedings of the 17th International Conference on Soil Mechanics on Soil Mechanics and Geotechnical Engineering: The Academia and Practice of Geotechnical Engineering, IOS Press. 3: 1873-1876.

Mohamad, H., Kueh, A.B.H., and Rashid, A. A. 2015. Distributed Optical-Fibre Strain Sensing in Reinforced Concrete Structures. Jurnal Teknologi (Sciences & Engineering). 74 (4): 93–97.

Poulos, H. 2005. Pile Behavior—Consequences of Geological and Construction Imperfections. J. Geotech. Geoenviron. Eng. 131(5): 538-563.

Thorburn, S., and Thorburn, J.Q. 1977. Review Of Problems Associated With The Constructionof Cast In Place Piles. CIRIA Report PG2. Storeys Gate, London.

El Wakil, A. Z., and Kassim, M. 2010. Bulging as a Pile Imperfection. Alexandria Engineering Journal. 49: 387– 391.

Fleming, K., Weltman, A., Randolph, M., and Elson, K. 2009. Piling Engineering. Taylor & Fancis, Abingdon & New York.

Randolph, M. F. 2003. RATZ 4.2 Manual: Load Transfer Analysis of Axially Loaded Piles. (Excel version)

Aoki, N., Velloso, D.A. and Salamoni, J.A. 1978. Fundações Para O Silo Vertical De 100000 T No Porto De Paranaguà , Sixth Brazilian Conference of Soil Mechanics and Foundation Engineering, Rio de Janeiro. 33: 125–132.

Viggiani, C., Mandolini, A., and Russo, G. 2012. Piles and Pile Foundations. Spon Press, London.

Chang, M. F., and Broms, B. B. 1991. Design of Bored Piles in Residual Soils based on Field Performance Data. Canadian Geotechnical Journal. 28: 200–209.

Seed, H. B, Idriss, I. M, and Arango, I. 1983. Evaluation of Liquefaction Potential using Field Performance Data. Journal of Geotechnical Engineering. 109 (3):458–82.

Anbazhagan, P., and Sitharam, T. G. 2010. Relationship between Low Strain Shear Modulus and Standard Penetration Test ‘N’ Values. ASTM Geotechnical Testing Journal. 33 (2):150–64.

Imai, T, and Tonouchi, K. 1982. Correlation of N-Value with S-Wave Velocity and Shear Modulus. Proceedings of the 2nd European Symposium on Penetration Testing. 57–72.

Ohsaki, Y., and Iwasaki, R. 1973. On Dynamic Shear Moduli and Poisson’s Ratio of Soil Deposits. Soils and Foundations. 13(4):61–73.

Reese, L. C. and O'Neill, M. W. 1988. Drilled Shaft: Construction and Design. Federal Highways Administration Report No. HI-88-042. Washington, D.C.

Decourt, L. 1995. Prediction of Load–Settlement Relationships for Foundations on the Basis of SPT, Ciclo de Conferencias Internationale “Leonardo Zeevaertâ€. UNAM Mexico: 85–104.






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