宏弯损耗的分布式光纤监测系统与边坡应用研究

发布时间：2018-06-16 22:56

  本文选题：边坡形变 + 分布式光纤传感网　； 参考：《昆明理工大学》2015年硕士论文

【摘要】：光纤弯曲半径大于纤芯半径时会引起光纤的宏弯损耗,利用光纤宏弯损耗的机制将光纤植入到被测构件中,通过基于瑞利散射的分布式光纤监测系统监测光纤链路损耗点位置和损耗信息判别构件断裂点和变形位置。本文以工程应用为基础,利用基于宏弯损耗的分布式光纤传感器监测技术对边坡表面变形进行实时监测。搭建了4通道的分布式监测系统和实时在线的边坡表面形变监测系统,实现了对边坡表面变形和裂缝的有效监测。主要研究内容如下：(1)根据宏弯损耗的分布式光纤传感器检测原理,通过对瑞利后向散射光功率监测检测宏弯损耗位置和损耗信息。实现四通道光时域反射仪硬件设计,包括OTDR模块选型、光开关模块选型、电源电路、光开关控制电路,并开发了四通道光时域反射仪上位机软件。通过对系统进行测试,测试结果表明,在脉冲宽度为5ns其事件盲区≤3m。(2)利用光纤宏弯损耗原理将分布式光纤传感网通过表面粘贴方式与菱形布设方法,将993m紧套光纤布设在上下边坡,实现边坡表面变形与裂缝位置信息的监测。开发了分布式光纤传感网边坡表面形变监测系统,对山地变电站边坡变形进行在线监测。3个月的监测结果表明,在2014年8月份发现在边坡928.37m出现非反射事件,损耗值为2.5dB,说明该处存在变形。
[Abstract]:When the bending radius of fiber is larger than the radius of fiber core, it will lead to the loss of optical fiber, so the optical fiber can be implanted into the tested component by the mechanism of fiber macro bending loss. A distributed optical fiber monitoring system based on Rayleigh scattering is used to monitor the location of the loss point and the loss information of the optical fiber link to distinguish the breaking point and the deformation position of the component. In this paper, based on engineering application, real-time monitoring of slope surface deformation is carried out by using distributed optical fiber sensor monitoring technology based on macro bending loss. A 4-channel distributed monitoring system and a real-time on-line monitoring system for slope surface deformation are set up, which can effectively monitor the surface deformation and crack of the slope. The main research contents are as follows: (1) according to the principle of distributed optical fiber sensor, the position and loss information of macro bending loss are detected by Rayleigh backscattering light power monitoring. The hardware design of four-channel optical time domain reflectometer is realized, including OTDR module selection, optical switch module selection, power supply circuit, optical switch control circuit, and the host computer software of four-channel optical time domain reflectometer is developed. By testing the system, the test results show that the distributed optical fiber sensor network is distributed through the surface paste and rhombus layout method using the principle of optical fiber macro bending loss when the pulse width is 5ns and the event blind area is 鈮，

本文编号：2028397