基于分布式光纤温度监测系统的集中渗漏通道流速计算模型

Computational model for dam leakage velocity in concentrated passage based on distributed optic fiber temperature sensing system

分布式光纤测温系统因其造价低、可实现实时快速分布式测温等优点,在堤坝渗漏监测方面具有良好的应用前景。但由于缺乏必要的理论基础和试验研究,目前分布式光纤测温的应用仅局限于渗漏定性分析,缺乏定量计算研究。根据分布式光纤温度监测系统在不加热和加热两种情况下的温度测量值,利用热平衡理论及坝体周围岩土体温度变化与集中渗漏流速关系建立数学物理模型,在层流和紊流两种不同流态下探讨了渗漏流速的确定方法。经过一个实例计算,验证了所推导公式的正确性,为分布式光纤测温在渗漏监测中的应用,提供了一个定量分析的依据。

The distributed optic fiber temperature sensing system has excellent application prospect in dam leakage monitoring for its advantages such as low cost and quick distributed temperature measurement.However,the deficiency of theoretical and experimental studies limits the use of the system in qualitative analysis and leads to the lack of quantitative calculation.By using the temperature data detected by the system under non-heated and heated conditions respectively,a mathematical physical model is established to describe the relationship between temperature variation of ambient rock-soil and leakage velocity according to the theory of heat transfer balance.The determinate method for the leakage velocity is proposed in accordance with flow regime as turbulent and laminar flows.A case study is provided to prove the validity of the proposed model.The model provides a quantitative analysis approach for the wide use of the distributed optic fiber temperature system in dam leakage monitoring.