温度分布式及裂缝监测的光纤传感技术在三峡工程中的应用

Application of temperature distribution and crack monitoring optical fiber sensing technology in the Three Gorges Project

三峡工程采用了光纤分布式测温系统。通过对其左岸电厂14号坝段浇筑过程中混凝土水化热的释放过程的监测研究表明,优选的光纤分布式温度测量系统安装方便,可快捷、准确地检测到坝体混凝土结构内部温度场的变化,有利于大坝的健康诊断和安全运行。在三峡工程泄洪16号坝段上游面垂直裂缝处布置和安装光纤测缝计的成活率为100%,监测表明,裂缝一直趋于闭合(受压),速率缓慢、平稳,逐渐趋于稳定。光纤测缝计同白光光纤信号调节器相连接,形成了绝对测量的光纤测缝系统,连接、检测均比较方便。

The Three Gorges Project used the distributed optical fiber temperature measurement system. Monitoring and study on the dissipation process of concrete hydration heat during concrete placement of the No.14 dam block of the left powerhouse showed that the optimum distributed optical fiber temperature sensing system for concrete temperature monitoring can be not only installed easily but also obtained the variation process of temperature inside dam block quickly and accurately. It is benefit for monitoring the safety information of dam. The optical fiber crack detectors were placed on the vertical cracks of the upstream surface of No.16 dam block of the spillway of the Three Gorges Project. The monitoring results for the vertical cracks indicated that the cracks have been tendency to close and have been gradually inclined to stability situation. The results showed that the optical fiber crack detectors placed on the cracks of the upstream surface of the spillway dam block of the Three Gorges Project are smart instruments and they were installed on the cracks successfully. Connecting an optical fiber joint meter with the white light signal controller for optical fiber, the absolute crack monitoring system with optical fiber sensing technology is formed, convenient to crack monitoring.