Fibre optic cables can be used as sensors to monitor temperature changes through the analysis of back scattered light. This can be linked to changes in the ambient conditions surrounding the fibre optic cable. Active distributed temperature sensing relies on an external heat source relative to the fibre optic cable to measure the properties of, and changes in, the surrounding medium. An experiment was conducted using distributed temperature sensing technology to monitor changes in sediment overburden for the purpose of determining whether scour could be measured above buried power cables containing fibre optic cables. Fibre optic cables were buried in a channel containing saturated sand and water with an external heat source. The depth of overburden sediment above the fibre optic cables was reduced, whilst the associated temperature response along the fibre optic cable was monitored. The data was matched to a finite element model so that the heat transfer taking place could be simulated and then the thermal conductivity of the soil modified to observe the potential changes in heat detected by the fibre optic cables. This paper explains the characteristics of heat transfer from an active heat source to the surrounding soil medium providing a means to translate the temperature measurement to the associated overburden thickness and to model the same response in different materials.

中文翻译：

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利用分布式温度传感检测沉积物上覆的变化：实验和数值研究

光纤电缆可以用作传感器，通过分析反向散射光来监视温度变化。这可能与光缆周围环境条件的变化有关。主动分布式温度感测依靠相对于光缆的外部热源来测量周围介质的特性和变化。为了确定是否可以在包含光纤电缆的埋入式电力电缆上方测量冲刷，使用分布式温度传感技术进行了一项实验，以监测沉积物覆盖层的变化。光缆被埋在带有饱和砂和水的通道中，并带有外部热源。减少了光缆上方的上覆沉积物深度，同时监测沿光缆的相关温度响应。将数据与有限元模型匹配，以便可以模拟发生的热传递，然后修改土壤的导热率，以观察光缆检测到的热量的潜在变化。本文解释了从活性热源到周围土壤介质的热传递特征，提供了一种将温度测量值转换为相关的覆盖层厚度并模拟不同材料中相同响应的方法。将数据与有限元模型匹配，以便可以模拟发生的传热，然后修改土壤的导热率，以观察光缆检测到的热量的潜在变化。本文解释了从活性热源到周围土壤介质的热传递特征，提供了一种将温度测量值转换为相关的覆盖层厚度并模拟不同材料中相同响应的方法。将数据与有限元模型匹配，以便可以模拟发生的热传递，然后修改土壤的导热率，以观察光缆检测到的热量的潜在变化。本文解释了从活性热源到周围土壤介质的热传递特征，提供了一种将温度测量值转换为相关的覆盖层厚度并模拟不同材料中相同响应的方法。