分布式光纤测温系统在景洪电站大坝混凝土温度监测中的应用研究

Application research on temperature monitoring in concrete of Jinghong hydropower station by distributed optical fiber temperature measurement system

本文基于分布式光纤测温的技术优势,对传统的测温光纤结构进行了改进,并成功地应用于景洪电站大坝混凝土温度和渗流定位监测,属于国内首创。在目前国内没有相应规范参考的前提下,首创性地提出了对这一特殊结构形式测温光缆的温度检验方法,并介绍了该光缆的铺设工艺和实测成果。改进后的测温光缆在碾压混凝土中的埋设成活率为100%,光纤温度分辨率为0.5℃,空间分辨率为0.5m。实测成果表明分布式光纤测温系统能快捷、准确地监测大坝混凝土结构内部温度场的变化,为有效地评价大坝安全提供了可靠的科学依据,具有较大的工程应用价值。

The advantages of distributed optical fiber temperature measuring system are introduced in this paper. After modification of the traditional structure of the optical fiber, it is the first time of measuring temperature and seepage position of the concrete in Jinghong hydropower project. The way of laying out the temperature measurement optical fiber in different concrete layers of the dam is introduced and the experience of controlling the radius and space location of the optical fiber is summarized. The methods of temperature rating and the specially structured temperature measurement of optical fiber are presented. The distributed optical fiber temperature measurement system, the law of temperature variation, the distribution of temperature in various layers and the peak values of temperature are studied. The measured results show that distributed optical fiber temperature measurement system can quickly and accurately monitor the variation of the temperature field within the dam concrete structure. These results have provided the reliable scientific basis for appraisal of safety and stabiity of the dam.