DEFORMATION SENSING METHOD OF SHIELD TUNNEL
BASED ON OPTICAL FIBER SENSING TECHNOLOGY OF BOTDA
WANG Fei1,2,HUANG Hongwei1,2,ZHANG Dongmei1,2,ZHANG Wei1,2,XU Ran1,2
(1. Department of Geotechnical Engineering,Tongji University,Shanghai 200092,China;2. Key Laboratory of Geotechnical and Underground Engineering of Ministry of Education,Tongji University,Shanghai 200092,China)
Abstract:Transverse deformation is basically regarded as a key index to evaluate structural behaviors of shield tunnels. The joint stiffness in shield tunnel is always weaker than segmental lining. Therefore the transverse deformation of shield tunnel is mainly governed by opening of joint and rotation of segmental lining. This paper presents a deformation sensing method using two-point fixed pretension fiber based on distributed optical fiber sensing technology,i.e. Brillouin optical time domain analysis(BOTDA). Both the spatial resolution of analyzer and the pattern of transverse deformation of shield tunnel are considered in this method. Geometrical analysis is used to calculate the opening of joint,rotation of segmental lining and deformation of tunnel. Two laboratory segmental joint tests of full-scale shield tunnel with different axial loads are conducted to verify this method. Test results indicate that this method is efficient in sensing the deformation of shield tunnel. Furthermore,monitoring density of shield tunnel deformation can be significantly increased using this method. Using this long-distance,high-density,high-accuracy and low-cost healthy monitoring method,the safety of metro tunnel operation can be greatly ensured.
叶耀东,朱合华,王如路. 软土地铁运营隧道病害现状及成因分析[J]. 地下空间与工程学报,2007,3(1):157-166.(YE Yaodong,ZHU Hehua,WANG Rulu. Analysis of the current status of metro operating tunnel damage in soft ground and its causes[J]. Chinese Journal of Underground Space and Engineering,2007,3(1):157-166.(in Chinese))
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