Based On The Principle Of Distributed Optical Fiber Sensing Earth Dam Seepage Monitoring Explore

Dam seepage monitoring is the assurance of dam safe operation, not only can provide solutions for the dam operation, but also provide a reference for dam maintenance.China is a country with the largest number of reservoir.the dam seepage monitoring innovativc,pioneering research has important significance..the traditional means of monitoring the seepage has not been adapt to the needs of automated monitoring, with the development of fiber optic temperature sensing technology, the use of distributed fiber optic temperature sensing technology for earth dam seepage monitoring has become the current hot and cutting-edge scientific research.so, exploring distributed optical fiber temperature sensor technology in the earth dam seepage monitoring field of layout, transformation theory, calculation equation for water conservancy project, construction and dam safety guarantee is very necessary.This topic Combined with the national natural science fund projects (51069003),using of distributed fiber optic temperature sensing technology, the earth dam seepage monitoring are carried out systematic research, the main research program include:model building, theoretical analysis, model validation. The main research contents include the following aspects:(1) Temperature variation of earth dam and seepage model. By analyzing the stable temperature field of dam seepage dam and the occurrence of changes in temperature, combined with porous media heat conduction and thermal convection, the initial establishment of the dam changes the temperature field and seepage model.(2) fiber Raman(Raman) scattering of spontaneous monitoring seepage model.by theory of spontaneous Raman scattering optical fiber and optical time domain reflectometry (OTDR), getting the temperature of the real-time monitoring of the dam, by analysis the changes of dam body temperature,the dam seepage conditions (velocity of flow) can be preliminary judged.(3) Mandatory monitoring of the heating fiber percolation model.using the optical fiber two dam between solid and liquid thermal conductivity and thermal convection, based on energy conservation, by in the heating process, the heated temperature change to determine seepage conditions (velocity of flow)of the specific parts of dam.(4) The model test of temperature field of seepage field. Using one-dimensional flow model tank tests, the theory of temperature changes reflecting seepage field theory has been analyzed,the reflecting theory has been tested and verified. (5) The study of layout of optical fiber in the dam. Focuses on the sensing fiber layout in the dam,fiber-geotextile, fiber-geomembrane coupled arrangement.(6) Exploiting seepage monitoring program. The program only put the automated monitoring idea, no the whole,systemic flow procedures.The results of the study indicate that:distributed optical fiber temperature sensor principle used for earth-rockfill dam seepage monitoring, have little interference, arrangement convenient, point optional, abnormal seepage feedback timely, monitoring accuracy to meet demand and other advantages. With further deepening, distributed optical fiber sensor in the application of hydraulic monitoring will certainly to obtain the significant expansion.