A bored pile deficiency detection method based on optical fiber temperature measurement

Henglin Xiao, Xilin Cui, Wenkai Lei

Institute of Geotechnical Engineering and Underground Construction, School of Civil Engineering and Architecture, Hubei University of Technology, Wuhan, 430068, China

Optical Fiber Technology, Volume 21, January 2015, Pages 1–6

Abstract

In this paper, a new deficiency detection method for bored piles is proposed based on the optical fiber temperature measurement. In this method, only one optical fiber cable is adopted for both measurement and transmission. By studying the heat transfer process between optical fiber and bored pile, the basic principle of the distributed optical fiber technique for bored pile integrity assessment is described. The detection equation is also derived. In addition, model tests are carried out at different heating powers, and the results show the temperature rise in the optical fiber cable is in direct proportion to the heating power. Deficiencies can be identified from analyzing the coefficients in the temperature rise – heating power expressions. Moreover, different values of temperature rise in air and in concrete are obtained when a same heating power is applied. The results imply that the proposed optical fiber temperature measurement can be considered as a possible way of detecting the bored pile deficiency and its mode by analyzing the values of temperature rise.

Keywords

Optical fiber temperature measurement; Bored pile; Integrity; Pile foundation detection; Temperature

References

[1] H. Zhang, Detection and Treatment of Bored Piles, China Communications Press, Beijing, 2001.

[2] Y. Zhang, P. Qiu, Application of Ultrasonic Wave in Concrete Quality Detection, Chemical Industry Press, Beijing, 2006.

[3] J. Chen, F. Gao, Test and Measurement Technology of Modern Pile Foundation Engineering – New Technology, New Method, and New Equipment, Shanghai science and Technology Press, Shanghai, 2011.

[4] F. Chen, T. Xu, J. Chen, Pile Quality Detection Technology, China Building Industry Press, Beijing, 2003.

[5] J. Liu, Comprehensive Application of Detecting Technology on Pile Foundation, Central South University, Changsha, 2011.

[6] D. Liu, Analysis of Pile Integrity Quality Based on Dynamic Test, South China University, Hengyang, 2010.

[7] A. Mendez et al., Application of embedded optical fiber sensors in reinforced concrete buildings and structures, SPIE 1170 (1989) 6–069.

[8] R. Maaskant, T. Alavie, R.M. Measures, G. Tadros, S.H. Rizkalla, A. GuhaThakurta, Fiber-optic Bragg grating sensors for bridge monitoring, Cement Concr. Compos. 19 (1997) 21–33.

[9] B. Glisic, M. Badoux, J.P. Jaccoud, D. Inaudi, Monitoring of a subterranean structure with the SOFO system, Tunnel Manag. Int. 2 (8) (2000) 22–27.

[10] N. Yasue, H. Naruse, J.I. Masuda, H. Kino, T. Nakamura, T. Yamaura, Concrete pipe strain measurement using optical fiber sensor, IEICE Trans. Electron E83-C (3) (2000) 468–474.

[11] C. Schilder, H. Kohlhoff, D. Hofmann, F. Basedau, W.R. Habel, M. Baeßler, E. Niederleithinger, S. Georgi, M. Herten, Static and dynamic pile testing of reinforced concrete piles with structure integrated fibre optic strain sensors, Proc. SPIE 8794 (2013) 879447-1–879447-4.

[12] C. Schilder, H. Kohlhoff, D. Hofmann, W.R. Habel, Structure-integrated fibreoptic strain wave sensor for pile testing and monitoring of reinforced concrete piles, NDT.net-The e-Journal of Nondestructive Testing 2013–04.

[13] M. Schallert, D. Hofmann, W.R. Habel, J. Stahlmann, Structure-integrated fiberoptic sensors for reliable static and dynamic analysis of concrete foundation piles, Proc. SPIE 6530 (2007). 65300D-1–65300D-14.

[14] C. Baldwin, T. Poloso, P. Chen, J. Niemczuk, J. Kiddy, C. Ealy, Structural monitoring of composite marine piles using fiber optic sensors, Proc. SPIE 4330 (2001) 487–497.

[15] G. Kister, D. Winter, Y.M. Gebremichael, J. Leighton, R.A. Badcock, P.D. Tester, S. Krishnamurthy, W.J.O. Boyle, K.T.V. Grattan, G.F. Fernando, Methodology and integrity monitoring of foundation concrete piles using Bragg grating optical fibre sensors, Eng. Struct. 29 (2007) 2048–2055.

[16] S. Nan, Q. Gao, Application of distributed optical fiber sensor technology based on BOTDR in similar model test of backfill mining, Procedia Earth Planet. Sci. 2 (2011) 34–39.

[17] H. Jiang, BOTDA distributed optical fiber sensing technology and its application in the test pile, Rock Soil Mech. 32 (10) (2011) 3190–3195. 

[18] C. Piao, B. Shi, G. Wei, Application of distributed optical fiber sensing technology in bored pile detection, J. Geotech. Eng. 30 (7) (2008) 976–981.

[19] J. Song, X. Bai, H. Ren, Application of distributed optical fibers in foundation pile static loading test, J. Henan Univ. 41 (4) (2011) 429–432.

[20] J. Song, H. Ren, X. Zhao, Distributed optical fiber monitoring of strain of large diameter and super-long reinforced concrete pile with post grouting, J. Pingdingshan Inst. Technol. (2001).

[21] H. Xiao, D. Cai, J. He, Measuring method of geomaterial thermal conductivity based on distributed optical fiber sensing technology, Chin. J. Rock Mech. Eng. 28 (4) (2009) 819–826.

[22] H. Xiao, J. Zhang, J. He, Research on measuring method of flow velocity based on distributed optical fiber sensing technology, Rock Soil Mech. 30 (11) (2009) 3543–3547.

[23] A.G. Loudon, E.F. Stacy, The thermal and acoustic properties of lightweight concretes, Struct. Concr. 3 (2) (1966) 58–95.

[24] B. Zhu, Mass Concrete Temperature Stress and Temperature Control, China Electric Power Press, China, 1999.