苏州轨道交通盾构隧道施工与运营期BOFDA监测技术研究

盾构隧道越来越广泛的应用于地下交通工程及地下管道构筑物中，其结构健康监测是保障隧道长期健康服役和反馈隧道安全隐患的重要课题。布里渊光频域分析技术（Brillouin Optical Frequency Domain Analyzer，BOFDA）是近年来国际上发展起来的分布式光纤传感新技术，并开始应用于岩土体内部变形的监测。本文依托苏州轨道交通盾构隧道结构健康监测项目，将基于BOFDA的分布式光纤感测技术应用于盾构隧道施工和运营期的结构安全健康监测。作者设计了可行的监测方案，研发了合理的光纤传感器及配套夹具，对隧道环向收敛、纵向沉降以及伸缩缝的变形进行了监测，取得了一批反映盾构隧道施工和运营期的结构安全健康监测数据，并对隧道的健康状态进行了分析。监测结果表明：BOFDA技术可有效地对隧道结构变形异常点、渗漏点和管片错动处等准确定位和监测，具有分布式、长距离、耐腐蚀、成活率高等技术优势，是地铁盾构隧道施工和运营期结构健康监测的一种十分有效的新手段。

RESEARCH ON THE APPLICATION OF BOFDA MONITORING TECHNOLOGY TO THE CONSTRUCTION AND OPERATION OF SUZHOU METRO SHIELD TUNNEL

Shield tunnel is more and more widely used in underground traffic engineering and underground pipeline structures. Shield tunnel structure health monitoring is an important project to ensure the long-term health of the tunnel and the safety of the tunnel. BOFDA is a new technology of distributed optical fiber sensing developed in recent years and has begun to apply to monitoring the interior deformation of rock mass and soil mass. In this paper, according to the Suzhou metro shield tunnel structural health monitoring project, the distributed optical fiber sensing technology based on BOFDA is applied to the construction and operation of the shield tunnel structure's safety and health monitoring. The writer formulates detailed and feasible monitoring scheme, designs the reasonable optical fiber sensor and the supporting fixture to monitor the tunnel's circumferential convergence, longitudinal settlement and expansion joints and analyzes the tunnel's health status using the data reflecting the shield tunnel structure's safety and health condition got from the monitor. The monitoring results have shown that BOFDA can position and monitor the places of abnormal deformation, common tunnel leakage and segment dislocation precisely and effectively. Also, BOFDA has the technical advantages of distributed, long distance, corrosion resistance and high survival rate and it's a new and effective method to monitor the shield tunnel structure's safety and health status during the construction and operation period.