高坝变形监测的多功能光纤传感系统与关键技术

The key technologies of the multi-functional distributed fiber-optic sensing system based on Brilliouin scattering principle for deformation monitoring of high earth-rock dams are investigated. On the basis of deformation theory of elastic circular beams, for first time presented are a novel fiber-optic monitoring tube, integrated 4 sensing fibers into a zigzag tube, and its layout across with rivers. This novel technology offers the integrative multi-function for monitoring of settlements, bi-directional horizontal displacements, interface slides and cracks of earth-rock dams. the fiber-optic sensing system can be laid on the surface of fill layers of the earth-rock dam body in a short time using the fiber-optic laying method with compress air.. Presented are the modelling theory and numerical simulation method of the micromechanical behaviors and mechanics-optics coupting effects of the fiber-optic-monitoring tube-soil complex in the Brillouin sensing technology, as well as the numerical integral method of the optical effects of nonlinear strain gradient, and the multi-parameter treatment method of the strong nonlinear strain distribution in the cracking area and crack location and width.. A series of verification experiments will be preformed, including the mechanics-optics coupling experiments with new types of PPP-BOTDA and MTS expirement system, as well as the comprehensive experiments of the earth-rock dam model.. The multi-funtional distributed sensing technology and system for deformation monitoring of high earth-rock dams are possessed of tri-superiorty including their multi-function,simplified system and integral high-speed laying in the dam body.

研究高土石坝变形监测的基于布里渊原理的多功能-分布式光纤传感技术体系和关键技术。依据圆管形弹性梁变形理论，首次提出4路传感光纤与波纹管集成的光纤监测管及其在坝体填筑层面上跨河向水平布置方法，具有可同时观测沉降、双向水平位移、界面错动、裂缝等多个项目一体化的监测功能。并运用光纤吹敷等技术，实现光纤系统在大坝填筑层面上的一次性整体敷设，显著提高存活率。提出布里渊传感光纤-监测管-土体复合体的细观力学和力-光耦合建模理论与数值模拟方法；提出非线性应变梯度的光学效应的数值积分算法和裂缝区局部强非线性应变与缝位-缝宽的多参量综合确定方法。采用新型的PPP-BOTDA解调仪和MTS刚性机构建精密力-光耦合实验系统，以及土石坝大比尺综合实验模型，进行多工况系列实验验证。学术思路新颖，赋予本项新系统具有多功能化、系统紧凑结构简化、整体快速敷设的三重优势，有利于推动高坝监测科技升级的重点突破。

提出高坝变形监测的布里渊型分布式光纤传感集成系统与技术方案以及传感光纤的平板型2维封装结构，具有多功能化-系统简练结构紧凑-整体快速敷设-保障光纤存活的多重优势。运用物理模型与数值模型的宻切相结合，对光纤封装件-土料复合体，进行实验验证。首次提出光纤在坝体填筑层面上跨河向布置方式及其在坝基-坝肩中的布置方式。构建了适用于土质心墙型-砼靣板型-土工膜防渗型土石坝以及双曲拱坝等各种常用坝型的布置方式和技术方案，适用范围广，具有工程实用价值；可实现在线遥测-珍断-预警，推动高坝安全监测科技升级的重点突破;已与水电工程设计方，协议一致、确定本成果在一座明年兴建的国外大坝中应用。提出双曲拱坝所特需的光纤封装的微弯梁-弱曲梁的弹性理论分析方法，具有学术价值。