Monitoring and warning of landslides and debris flows using an optical fiber sensor technology

Authors: Pei Huafu (1) ; Cui Peng (2) ; Yin Jianhua (1) ; Zhu Honghu (3) ; Chen Xiaoqing (2) ; Pei Laizheng (2) ; Xu Dongsheng (1)

Affiliations:
(1) Department of Civil and Structural Engineering, the Hong Kong Polytechnic University, Hong Kong, China
(2) Institute of Mountain Hazards and Environment, CAS, 610041, Chengdu, China
(3) School of Earth Sciences and Engineering, Nanjing University, 210093, Nanjing, China

Source: Journal of Mountain Science, Volume 8, Number 5, 728-738, DOI: 10.1007/s11629-011-2038-2

Fulltext link: http://www.springerlink.com/content/5w478501v7513jl7/

Abstract: Landslides and debris flows are typical geo-hazards which occur in hilly or mountainous regions. Debris flows may result from landslides. Geotechnical instrumentation plays an important role in monitoring and warning of landslides and resulted debris flows. Traditional technologies for monitoring landslides and debris flows have certain limitations. The new optical fiber sensors presented in this paper can overcome those limitations. This paper presents two new optical fiber sensor systems: one is the Fiber Bragg Grating (FBG)-based in-place inclinometer for monitoring landslides and the other is the FBG-based column-net system for monitoring debris flows. This paper presents the calibration results of FBG-based in-place inclinometers in laboratory. It is found that the calibration results are in good agreement with theoretical results. Both the FBG-based in-place inclinometers and the FBG-based column-net system have been installed at a site in Weijiagou valley, Beichuan County, Sichuan Province of China. Some preliminary results have been obtained and reported in the paper. The advantages of the FBG monitoring systems and their potential applications are also presented.

Keywords: Landslide; Debris flow; Fiber Bragg Grating; In-place inclinometer; Column-net system

References:

  1. Cui P, Chen XQ, Zhu YY, Su FH, Han YS, Liu HJ, Zhuang JQ (2011) The Wenchuan Earthquake (May 12, 2008), Sichuan Province, China, and resulting geohazards. Natural Hazards. 56:19-36.
  2. Cui P, Zhu, YY, Han YS, Chen XQ, Zhuang JQ (2009) The 12 May Wenchuan earthquake-induced landslide lakes: distribution and preliminary risk evaluation. Landslides. 6(3):209-223.
  3. Dunnicliff J (1993) Geotechnical Instrumentation for Monitoring Field Performance. New York, John Wiley & Sons.
  4. Ho YT, Huang, AB, Lee JT (2006) Development of a fibre Bragg grating sensored ground movement monitoring system. Measurement Science and Technology 17(7): 1733-1740.
  5. Hill KO, Fujii F, Johnson DC, Kawasaki BS (1978) Photosensitivity on optical fiber waveguides: application to reflection filter fabrication. Applied Physics Letters 32(10): 647-649.
  6. Hisham M, Kenichi S, Adam P, Peter JB (2011) Performance monitoring of a secant piled wall using distributed fiber optic strain sensing. Journal of Geotechnical and Geoenvironmental Engineering. Doi:10.1061/(ASCE)GT.1943-5606.0000543.
  7. Lin YL, Lin KH, Chen MH, Lin WW (2007) A debris flow monitoring system by means of fiber optic interferometers. Proceedings of SPIE, Fiber Optic Sensors and Applications V. Boston, USA. pp 6770: 67700Z.1-67700Z.8.
  8. Morey WW, Meltz G, Glenn, WH (1989). Fiber Optic Bragg Grating sensors. Proceedings of SPIE, Boston. 1169: 98-107.
  9. Moyo P, Brownjohn JMW, Suresh R, Tjin SC (2005) Development of fiber Bragg grating sensors for monitoring civil infrastructure. Engineering Structures 27(12): 1828-1834.
  10. Othonos A, Kalli K, Kalli K (1999). Fiber Bragg gratings: fundamentals and applications in telecommunications and sensing. Artech House, Boston.
  11. Pei HF, Yin JH, Zhu HH, Hong CY (2010) In-place displacement monitoring and stability evaluation of slope based on FBG sensing technology. Chinese Journal of Rock Mechanics and Engineering 29(8): 1570-1576. (In Chinese)
  12. Posey RJ, Vohra ST (1999) An eight-channel fiber-optic Bragg grating and stimulated Brillouin sensor system for simultaneous temperature and strain measurements. Photonics Technology Letters 11(12): 1641-1643.
  13. Sichuan Institute of Geological Engineering Investigation (2009) Report on emergency investigation of Beichuan Couty Xishan landslide group (debris flow). (In Chinese)
  14. Tang C, Zhu J, Li WL, Liang JT (2009) Rainfall-triggered debris flows following the Wenchuan earthquake. Bulletin of Engineering Geology and the Environment 68(2): 187-194.
  15. Yin JH, Zhu HH, Fung KW, Jin W, Mak LM, Kuo K (2008) Innovative optical fiber sensors for monitoring displacement of geotechnical structures. The HKIE Geotechnical Division 28th Annual Seminar, Hong Kong: 287-294.
  16. Yoshida Y, Kashiwai Y, Murakami E, Ishida S, Hashiguchi N (2002) Development of the monitoring system for slope deformations with fiber Bragg grating arrays. Proceedings of SPIE, Smart Structures and Materials 2002: Smart Sensor Technology and Measurement Systems. San Diego, USA. pp296-303.
  17. Zhuang JQ, Cui P, Hu KH, Chen XQ, Ge YG (2010) Characteristics of Earthquake-Triggered Landslides and Post-Earthquake Debris Flows in Beichuan county. Journal of Mountain Science 7(3): 246-254.
  18. Zhu HH, Yin JH, Zhang L, Jin W, Dong JH (2010) Monitoring internal displacements of a model dam using FBG sensing bars. Advances in Structural Engineering 13(2): 249-262.