DOI QR코드

DOI QR Code

BOTDA based water-filling and preloading test of spiral case structure

  • Cui, Heliang (School of Earth Sciences and Engineering, Nanjing University) ;
  • Zhang, Dan (School of Earth Sciences and Engineering, Nanjing University) ;
  • Shi, Bin (School of Earth Sciences and Engineering, Nanjing University) ;
  • Peng, Shusheng (Zhejiang Huadong Engineering Safety Technology Co.,Ltd.)
  • 투고 : 2017.07.30
  • 심사 : 2017.12.13
  • 발행 : 2018.01.25

초록

In the water-filling and preloading test, the sensing cables were installed on the surface of steel spiral case and in the surrounding concrete to monitor the strain distribution of several cross-sections by using Brillouin Optical Time Domain Analysis (BOTDA), a kind of distributed optical fiber sensing (DOFS) technology. The average hoop strain of the spiral case was about $330{\mu}{\varepsilon}$ and $590{\mu}{\varepsilon}$ when the water-filling pressure in the spiral case was 2.6 MPa and 4.1 MPa. The difference between the measured and the calculated strain was only about $50{\mu}{\varepsilon}$. It was the first time that the stress adjustment of the spiral case was monitored by the sensing cable when the pressure was increased to 1 MPa and the residual strain of $20{\mu}{\varepsilon}$ was obtained after preloading. Meanwhile, the shrinkage of $70{\sim}100{\mu}{\varepsilon}$ of the surrounding concrete was effectively monitored during the depressurization. It is estimated that the width of the gap between the steel spiral case and the surrounding concrete was 0.51 ~ 0.75 mm. BOTDA based distributed optical fiber sensing technology can obtain continuous strain of the structure and it is more reliable than traditional point sensor. The strain distribution obtained by BOTDA provides strong support for the design and optimization of the spiral case structure.

키워드

과제정보

연구 과제 주관 기관 : National Natural Science Foundation of China, Natural Science Foundation of Jiangsu Province

참고문헌

  1. Bao, Y., Tang, F.J., Chen, Y.Z., Meng, W.N., Huang, Y. and Chen, G.D. (2016), "Concrete pavement monitoring with PPP-BOTDA distributed strain and crack sensors", Smart Struct. Syst., 18(3), 405-423. https://doi.org/10.12989/sss.2016.18.3.405
  2. Bao, X.Y. and Chen, L. (2012), "Recent progress in distributed fiber optic sensors", Sensors, 12(7), 8601-8639. https://doi.org/10.3390/s120708601
  3. Culverhouse, D., Farahi, F., Pannel, C.N. and Jackson, D.A. (1989), "Potential of stimulated Brillouin scattering as sensing mechanism for distributed temperature sensors", Electron. Lett., 25(14), 913-915. https://doi.org/10.1049/el:19890612
  4. Ding, C.Q. (2011), "Monitoring result after keeping the pressure and temperature in spiral case of left bank house", Hydropower Autom. Dam Monit., 35(2), 67-71.
  5. Horiguchi, T., Kurashima, T. and Tateda, M. (1989), "Tensile strain dependence of Brillouin frequency shift in silica optical fibers." IEEE Photonics Technol. Lett., 1(5), 107-108. https://doi.org/10.1109/68.34756
  6. Kishida, K., Li, C.H., Li, S.B. and Nishiguchi, K. (2004), "Pulsed pre-pump method to achieve centimeter order spatial resolution in Brillouin distributed measuring technique", IEICE Tech. Rep. OFT2004-28, 104(341), 15-20.
  7. Li, C.H., Tsuda, T. and Sawa, T. Makita, A., Takano, H., Kishida, K., Wu, Z.S., Takeda, N. and Minakuchi, S. (2008), "PPP-BOTDA method to achieve 10cm spatial resolution and 10Hz measuring speed in distributed sensing", IEICE Tech. Rep. OFT2008-42, 108(245), 39-44.
  8. Li, H., Ou, J. and Zhang, X. (2015), "Research and practice of health monitoring for long-span bridges in the mainland of China", Smart Structu. Syst., 15(3), 555-576. https://doi.org/10.12989/sss.2015.15.3.555
  9. Liu, R.M., Babanajad, S.K., Taylor, T. and Ansari, F. (2015), "Experimental study on structural defect detection by monitoring distributed dynamic strain", Smart Mater. Struct., 24, 115038. https://doi.org/10.1088/0964-1726/24/11/115038
  10. Shi, B., Zhang, D. and Zhu, H.H. (2011), "Application of distributed optical fiber strain measurement into geotechnical engineering monitoring", Proceedings of the 8th International Workshop on Structural Health Monitoring, Stanford, USA, September.
  11. Soga, K., Kwan, V., Pelecanos, L., Rui, Y., Schwamb, T., Seo, H. and Wilcock, M. (2015), "The role of distributed sensing in understanding the engineering performance of geotechnical structures", Proceedings of the 16th ECSMGE-Geotechnical Engineering for Infrastructure and Development, Edinburgh, UK, January.
  12. Xue, Y., Cheng, W.B. and Zhang, M. (2012), "Analysis on hydrostatic test of hydraulic turbine spiral case of Nuozhadu hydropower station", Yangtze River, 43(4), 67-69.
  13. Yamauchi, Y., Guzik, A., Kishida, K. and Li, C.H. (2007), "A study on the stability, reliability, and accuracy of neubrescope-based pipe thinning detection system", SHMII-3, Vancouver, British Columbia, Canada November 13-16.
  14. Zhang, C.S., Chu, W.J., Liu, N., Zhu, Y.S. and Hou, J. (2011), "Laboratory tests and numerical simulations of brittle marble and squeezing schist at Jinping II hydropower station China", J. Rock Mech. Geotech. Eng., 3(1), 30-38. https://doi.org/10.3724/SP.J.1235.2011.00030
  15. Zhang, D., Cui, H.L. and Shi, B. (2013), "Spatial resolution of DOFS and its calibration methods", Opt. Laser. Eng., 51, 335-340. https://doi.org/10.1016/j.optlaseng.2012.10.009
  16. Zhang, D., Wang, J.C. and Li, B. (2016), "Fatigue characteristics of distributed sensing cables under low cycle elongation", Smart Structu. Syst., 18(6), 1203-1215. https://doi.org/10.12989/sss.2016.18.6.1203