THE BOTDR- BASED STRAIN MONITORING FOR TUNNEL

ZHANG Dan SHI Bin XU Hongzhong

Advanced Computational Engineering Institute for Earth Environment, Nanjing University, Nanjing 210093

Abstract  

Brillouin Optical Time - Domain Reflectometer (BOTDR) is a newly developed distributed measuring technique for st rains. In this paper , the merit s and the basic measurement principle of BOTDR is presented. The feasibility and advantages of the distributed st rain monitoring of structures in geotechnical engineering are demonstrated by a case study for st rain monitoring in a tunnel. At the end , several key issues for applications of BOTDR are discussed , including enhancement of spatial resolution , layout of the sensing optical fiber and the health monitoring and damage diagnosis.

Key words  BOTDR, Distributed optical fiber sensing, Brillouin scattering, Tunnel

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