基于碳纤维加热光缆的砂性土渗流场C-DTS分布式监测试验研究

岩土体中渗流场的监测是岩土工程防灾减灾中一项必不可少的基础工作。在总结已有监测方法优缺点的基础上，提出了渗流场碳纤维加热光缆的分布式温度光纤感测技术（简称C-DTS）；介绍了该方法的监测原理；提出了温度特征值（ ）的概念；设计了砂性土渗流模拟装置，并对砂性土中不同渗流速率下的渗流场进行了室内试验。通过试验确定了 与渗流速率（V）之间存在线性关系；证明了碳纤维加热光缆能够有效地提高DTS监测的敏感性，可实现渗流速率的分布式监测。对该方法应用于工程实践还需要开展的研究工作进行了分析。

Experiment study of seepage field monitoring in sandy soil using carbon coated heating optical fiber-based C-DTS

The seepage field monitoring of sandy soil is a necessary and basic work for disaster prevention and mitigation in geotechnical engineering. A distributed temperature system with the carbon coated heating optical fiber (C-DTS) is proposed on the basis of summarizing the advantages and disadvantages of the existing monitoring methods. The monitoring principle of the method is presented and the concept of the eigenvalue of temperature （ ）is introduced based on the thermal diffusion theory and Ohm’s Law. After that, a seepage field simulation device for sandy soil and monitoring program are designed as well. An indoor test of the seepage monitoring is run, the linear relationship of the eigenvalue of temperature ( ) and the seepage velocity (V) is defined at different seepage velocities in sandy soil. The temperature descends as the seepage velocity increases, and their relationship complies with the formula derivation. The experiment results show that C-DTS can effectively improve the sensitivity of DTS monitoring and realize fully-distributed monitoring of seepage velocity in geotechnical engineering. Finally, some related research work for further applying to geotechnical engineering practice has been analyzed.