Segment misalignment, joint opening, and segment rotation monitoring for tunnels using distributed optical fiber sensing

IF 7.4 1区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Tunnelling and Underground Space Technology Pub Date : 2025-09-17 DOI:10.1016/j.tust.2025.107087

Zihao Chen , Pengpeng Ni , Hongyuan Dong , Yuzhe Yang , Zhiwang Lu

{"title":"Segment misalignment, joint opening, and segment rotation monitoring for tunnels using distributed optical fiber sensing","authors":"Zihao Chen , Pengpeng Ni , Hongyuan Dong , Yuzhe Yang , Zhiwang Lu","doi":"10.1016/j.tust.2025.107087","DOIUrl":null,"url":null,"abstract":"<div><div>Distributed optical fiber sensing (DOFS) has been adopted in various applications due to its spatial continuity, good precision, and versatile adaptability. Currently, its use in monitoring the longitudinal deformations for tunnels remains limited. This study proposes an instrumentation method based on a “W”-shaped fiber layout configuration, and the associated analytical solutions for capturing different tunnel deformation modes (segment misalignment, joint opening, and segment rotation) are derived. The effectiveness of the proposed scheme is evaluated by laboratory experiments and others’ research. Results demonstrate that the theoretical model can accurately calculate coupled tunnel deformations. Given the operational strain range within 12,000 με for optical fibers, a pre-strain of 6,000 με is recommended during fiber installation to capture both tension and compression. Segment misalignment can cause small axial fiber strain (opening strain), when the segment misalignment displacement is within ± 0.004·<em>H</em> (<em>H</em> is the tunnel segment height). Notably, true misalignment requires correction by subtracting the opening error strain from the measured value. Optimal fiber layout with <em>b</em>/<em>H</em> = 0.6 (<em>b</em> is the vertical projection of the inclined fiber) is suggested to enable the measurements of segment misalignment up to 0.004·<em>H</em> and joint opening up to 0.006·<em>L</em> (<em>L</em> is the tunnel segment length).</div></div>","PeriodicalId":49414,"journal":{"name":"Tunnelling and Underground Space Technology","volume":"167 ","pages":"Article 107087"},"PeriodicalIF":7.4000,"publicationDate":"2025-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Tunnelling and Underground Space Technology","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0886779825007254","RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"CONSTRUCTION & BUILDING TECHNOLOGY","Score":null,"Total":0}

引用次数: 0

Abstract

Distributed optical fiber sensing (DOFS) has been adopted in various applications due to its spatial continuity, good precision, and versatile adaptability. Currently, its use in monitoring the longitudinal deformations for tunnels remains limited. This study proposes an instrumentation method based on a “W”-shaped fiber layout configuration, and the associated analytical solutions for capturing different tunnel deformation modes (segment misalignment, joint opening, and segment rotation) are derived. The effectiveness of the proposed scheme is evaluated by laboratory experiments and others’ research. Results demonstrate that the theoretical model can accurately calculate coupled tunnel deformations. Given the operational strain range within 12,000 με for optical fibers, a pre-strain of 6,000 με is recommended during fiber installation to capture both tension and compression. Segment misalignment can cause small axial fiber strain (opening strain), when the segment misalignment displacement is within ± 0.004·H (H is the tunnel segment height). Notably, true misalignment requires correction by subtracting the opening error strain from the measured value. Optimal fiber layout with b/H = 0.6 (b is the vertical projection of the inclined fiber) is suggested to enable the measurements of segment misalignment up to 0.004·H and joint opening up to 0.006·L (L is the tunnel segment length).

查看原文本刊更多论文

基于分布式光纤传感的隧道分段错位、接缝开口和分段旋转监测

分布式光纤传感以其空间连续性、精度好、适应性强等优点被广泛应用。目前，它在隧道纵向变形监测中的应用仍然有限。本研究提出了一种基于“W”形光纤布局配置的仪器方法，并推导了捕获不同隧道变形模式（段错位、接缝打开和段旋转）的相关解析解。通过实验室实验和其他研究对该方案的有效性进行了评价。结果表明，该理论模型能较准确地计算隧道耦合变形。考虑到光纤的工作应变范围在12,000 με以内，建议在光纤安装时使用6,000 με的预应变，以同时捕获拉伸和压缩。当管片错位位移在±0.004·H （H为隧道管片高度）以内时，管片错位引起的轴向纤维应变（开口应变）较小。值得注意的是，真正的不对准需要通过从测量值中减去开口误差应变来纠正。建议采用b/H = 0.6 （b为倾斜光纤的垂直投影）的最优光纤布置图，可以测量到0.004·H的管段偏差和0.006·L （L为隧道管段长度）的接缝开口。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

求助全文

约1分钟内获得全文求助全文

来源期刊

Tunnelling and Underground Space Technology 工程技术-工程：土木

CiteScore

11.90

自引率

18.80%

发文量

454

审稿时长

10.8 months

期刊介绍： Tunnelling and Underground Space Technology is an international journal which publishes authoritative articles encompassing the development of innovative uses of underground space and the results of high quality research into improved, more cost-effective techniques for the planning, geo-investigation, design, construction, operation and maintenance of underground and earth-sheltered structures. The journal provides an effective vehicle for the improved worldwide exchange of information on developments in underground technology - and the experience gained from its use - and is strongly committed to publishing papers on the interdisciplinary aspects of creating, planning, and regulating underground space.