寒区埋地管道的分布式结构健康监测与实时安全预警方法研究

Structural health monitoring and real-time safety warning for the buried pipeliens in the cold regions, based on the Brillouin distributed fiber optic sensing technique, will be studied in this project. To meet the requirements of the oil import, a large number of the oil pipelines are planing or under constructions in the cold regions in China such as northeast and west areas. The frost weave and thawing settlement has been the most dangerous threat to the safe operation of the pipelines, which occours at the masking locations underground. However, the damage mechnism of the buired pipelines induced by the frost heave and thawing settlement has not been fully revealed, and the structural health monitoring and safety assessment techniques cannot satisfy the needs of the real applicatons. The objectives of this project pertain to the pipeline damage due to the frost heave and thawing settlement. The Brillouin based fiber optic sensing technique will be stydied to simultaneously monitor the strain as well as the temperature for the buried pipelines in a distributed manner. The real-time monitoring of structural state and damage development will be achieved. The relationship between the typical damage in the pipe and the distributed strain will be stydied according to the large scale physical modeling simulations. Then the new methodologies will be built for structural damage diagnosis and the disaster inversion with the distributed monitoring data. The multi-level indices of the structural safety will be proposed, and the approaches will be put forward for the structural safety assessment and real-time safety warning. The achivements of this project could overcome the limiations of the existing techniques on the distributed monitoring and real-time safety waring. This project could provide the technical supports of the disaster prevention and service-life safe operation for the buried pipelines in the cold regions.

为了满足原油进口的需要，一大批输油管道工程已经或正在我国东北和西部等高寒地区规划建设。寒区输油管道在沿途任意地下隐蔽位置均可发生的冻胀融沉灾害，已经成为威胁管道安全运行的首要因素。但是，管道冻胀融沉灾害机理尚未完整揭示，结构健康监测与安全评估技术仍然相对落后。本课题针对寒区埋地管道的冻胀融沉灾害问题，旨在发展基于Brillouin光纤传感技术的长距离埋地管道的应变温度同步监测的分布式传感方法，实现埋地管道结构状态的实时监测；基于大尺度物理模拟揭示埋地管道典型损伤与分布式应变的对应关系，建立基于分布式监测信息的埋地管道冻胀融沉灾害反演与结构损伤诊断方法；确定寒区埋地管道的多水平安全指标体系，提出基于分布式监测信息的结构安全评估与实时预警方法。本课题研究成果将克服当前技术难以进行分布式监测与实时安全预警的局限性，为我国寒区埋地管道的冻胀融沉灾害预防和全寿命安全服役提供技术支撑。

根据项目任务书规定的研究内容，交叉采用理论分析、物理模拟和数值仿真的研究方法，系统开展了寒区埋地管道分布式结构健康监测与实时安全预警方法的研究，全面实现了预期目标。项目取得的创新性研究成果包括：（1）针对寒区埋地管道的主要失效模式，提出了适用于监测管道整体屈曲和基础沉降行为的分布式光纤监测方案，建立了长距离埋地管道的应变温度同步监测的分布式传感方法；（2）基于冻胀导致的管道屈曲发生机理确定了管道的屈曲敏感特征，建立了基于分布式应变监测数据的管道屈曲形状反演方法，实现了管道前、后屈曲行为的定量评估；（3）根据融沉导致的管-土相互作用机理，提出了利用分布式应变监测数据反演分段式管道结构状态的方法，实现了管身强度与管口变形的定量识别；（4）进行了管道在内压-轴力-弯矩联合作用下的破坏机理试验，获得了钢管的应变响应及其极限承载能力，同时开展了管道在各工况下弯曲反应的数值仿真研究，提出了临界屈曲应变计算公式，建立了埋地管道结构安全评估的准则和方法。以上研究成果为寒区埋地管道冻胀融沉灾害的监测及预警提供了科学方法，对于发展寒区埋地管道的结构安全评估及失效预防的理论和技术具有积极意义。.项目研究成果共发表学术论文20篇，已录用学术论文4篇，其中已被SCI收录5篇、EI收录10篇，做国内学术会议主题报告和特邀报告各1次。获授权发明专利1项、实用新型专利3项，另有2项发明专利已受理。获得软件著作权2项。