Abstract: The operating principles of seepage positioning and quantitative monitoring based on distributed optical fiber temperature sensing technique were introduced in this paper. The indoor seepage monitoring model and the ideal optical fiber arrangement method to improve the seepage monitoring spatial accuracy were designed. In order to determine the rationality of optical fiber bending radius, a temperature calibration test was carried out between the optical fiber winded on the PVC tubes and the unwinded optical fiber. Then, the seepage simulation test was implemented through heating the optical fiber buried in the clay, fine sand, and 4 kinds of mixed soil in which the quality ratio of clay and fine sand are 4∶1, 3∶2, 2∶3 and 1∶4, respectively. It proved the rationality of the optical fiber arrangement and the feasibility of seepage quantitative monitoring by comparing and analyzing the optical fiber temperature rise values of different seepage flows. In the end, the effective measures of improving the temperature measuring accuracy and compaction effect in the test were discussed.

Key words: distributed optical fiber temperature sensing, quantitative monitoring, spatial measurement precision, bending radius

摘要： 介绍了分布式光纤温度传感技术渗流定位和定量监测的工作原理；设计了室内渗流监测模型以及理想的提高渗流监测空间测量精度的光纤布置方式；通过对缠绕在PVC管上的光纤和未缠绕的光纤进行温度标定试验确定了光纤弯曲半径的合理性；通过对埋置于黏土、砂土以及黏土与砂土质量比分别为4∶1、3∶2、2∶3、1∶4的均匀混合土壤中的光纤进行加热模拟渗流试验，对比分析不同渗流量下光纤温降情况，说明光纤布置方式的合理性以及渗流定量监测的可行性；讨论了试验中关于提高温度测量精度以及压实效果的有效措施。

关键词: 分布式光纤温度传感, 定量监测, 空间测量精度, 弯曲半径