Life cycle detection of prestress in large prestressed reinforcement structures

Abstract

To monitor the stress state of prestressed reinforcement in large reinforcement prestressed structure, two sensing structures, namely the direct spiral-winding structure and sawtooth modulated structure, were designed based on the ordinary communication optical fiber. The sensing theories were analyzed, and the experimental studies were also carried out. The quasi-distributed sensing system based on optical time domain reflective technology was established. The detection wavelength and spatial resolution were analyzed, and the estimation formula of maximal number of sensing point was also given. The results show that the system can realize the quasi-distributed test of measurand with single fiber, which helps to simplify the in-out wires. Moreover it can take on the important task of long-term and continuous monitoring of prestress, which helps to realize the life cycle detection of prestress, and play an important role in the estimating of bridge health state.

Keywords

life cycle detection / smart structure / prestress / optical fiber / quasi-distribution

References

[1] ChenHung-liang, WissawapaisalK. Measurement of tensile forces in a seven-wire prestressing strand using stress waves[J]. Journal of Engineering Mechanics, 2001, 127(6): 599-606

[2] ChenHung-liang, WissawapaisalK. Application of wigner-ville transform to evaluate tensile forces in seven-wire prestressing strands[J]. Journal of Engineering Mechanics, 2002, 128(11): 1206-1214

[3] BouchillouxP, LhermetN, ClaeyssenF. Electromagnetic stress sensor for bridge cables and prestressed concrete structures [J]. Journal of Intelligent Material Systems and Structures, 2000, 10(5): 397-401

[4] TsamasphyrosG J, FurnarakisN K, KanderakisG N, et al.. Computational analysis and optimization for smart patching repairs [J]. Applied Composite Materials, 2003, 10: 141-148

[5] BronnimannR, NellenP M, SennhauserU, et al.. Application and reliability of a fiber optical surveillance system for a stay cable bridge [J]. Smart Mater Struct, 1998, 7(2): 229-236

[6] HuangMin-shuang, LiangDa-kai, YuanShenfang, et al.. Research on novel fiber optic sensing technology in the application of smart structures [J]. Acta Aeronautics Et Astronautics Sinica, 2001, 22(4): 326-329(in Chinese)

[7] HanLei, VoloshinA S. Studies on fiber optic sensory network in smart structures [J]. Acta Optica Sinica, 1999, 19(6): 757-761(in Chinese)

[8] AoyamaK, NakagawaK, ItohT. Optical time domain reflectometry in a single-mode fiber [J]. IEEE Journal of Quantum Electronics, 1981, 17(6): 862-868

[9] BlanchardP, ClinR, DucosL. Improvement on nonreflective event locating accuracy with OTDR [J]. Electronics letters, 1995, 31(23): 2034-2035

[10] GuXiang-lin, ChenZhong-yu, AnsariF. Embedded fiber optic crack sensor for reinforced concrete structures [J]. ACI Structural Journal, 2000, 97(3): 468-476

[11] OhnoH, NaruseH, KurashimaT, et al.. Application of Brillouin scattering-based distributed optical fiber strain sensor to actual concrete piles [J]. IEICE Trans Electron, 2002, E85-C(4): 945-951

[12] XieGuang-ping, KeeyS L, AsundiA. Optical time domain reflectometry for distributed sensing of the structural strain and deformation[A]. Conference on Advanced Photonic Sensors and Applications [C], 1999, Sungapore, SPIE: 497-504

[13] GengJun-ping, XuJia-dong, LiYan, et al.. Theoretical analysis of the fully distributed fiber optic sensor base on Raman optical-fiber frequency-domain reflectometry (ROFDR) [J]. Acta Photonica Sinica, 2002, 31(10): 1261-1265(in Chinese)

[14] TakadaK, HimenoA, YukimatsuK. High sensitivity and submillimeter resolution optical time-domain reflectometry based on low-coherence interference [J]. Journal of Lightwave Technology, 1992, 10(12): 1998-2005

[15] MasaruK, TaylorH F, TakadaK, et al.. Optical fiber component characterization by high-intensity and high-spatial-resolution interferometric optic-time-domain reflectometer [J]. IEEE Photonics Technology Letters, 1991, 3(6): 564-566