Study On The Method Of Leakage Detection And Disposal Monitoring In Reservoir Area Of Water Conservancy And Hydropower Projects

The effective detection and disposal of reservoir leakage of water conservancy and hydropower projects is related to the protection of water resources and hydropower energy and the safety of people’s property.Geophysical method has become a powerful means for seepage detection of dams and cofferdams due to its advantages of nondestructive detection.It is widely used in the face of the characteristics of numerous water conservancy and hydropower projects,complex geological environment,karst development and active tectonic movement in China.However,the reservoir leakage has the characteristics of concealment,many underwater detection interferences,great difficulty and limited equipment,which makes the research on reservoir basin and bank slope leakage detection relatively weak,greatly limiting the application of relevant theories and hardware breakthroughs and electrical detection.In this paper,physical simulation,numerical simulation,AI(artificial intelligence)noise reduction,and leakage disposal monitoring system design and material selection based on electrical characteristics are carried out through the flume experiment,and the innovative method of this paper is verified to be scientific and feasible in combination with the disaster field test in Pingwu County.Firstly,the leakage characteristics are characterized by experimental measurement,and the effectiveness and interference factors of DC leakage detection are analyzed through model and theoretical analysis experiments;Secondly,the noise interference caused by water flow is processed by AI based deep neural network noise reduction,and the noise reduction results of dynamic and static water data are compared and analyzed to verify the reliability of AI noise reduction based on a priori condition algorithm;Thirdly,based on the physical basis of the difference in electrical characteristics and the mechanism of leakage grouting disposal,the monitoring system design and grouting base material selection experiments were carried out,which verified the applicability of the method;Finally,in combination with the site hydrogeology,engineering geology,tectonic geology and other environments of Pingwu County,the practicability of leakage detection and disposal in the reservoir area of systematic water conservancy and hydropower projects is discussed,providing technical support for the construction and safe operation of typical water conservancy and hydropower projects in the Fujiang River and Minjiang River basin located at the northern edge of the Longmen Mountain activity belt.Through the research,the following understandings are obtained:(1)The response characteristics of DC underwater leakage detection in the reservoir area are clarified,and five influencing factors and time-lapse detection are analyzed.The concealment and multiple interference factors of the reservoir leakage need to be carried out by means of underwater measurement.The characteristics of low resistivity model anomaly and high resistivity anomaly at different locations in the reservoir area are analyzed through experiments,which confirms the effectiveness of underwater DC method on existing leakage(low resistivity anomaly)and hidden karst or fissure(high resistivity anomaly);Through experiments and theoretical models,the influence and degree of underwater DC current caused by different measuring line depths,different water depths,different silt thicknesses,different water resistivity and noise interference are analyzed.The measuring line is far away from leakage and cannot obtain effective information in depth.The low resistivity water body and thick silt layer will shield the current field to transmit downward.The deep-water environment will interfere with the measurement effect,and the noise will cause false abnormal information;Through time-lapse measurement,it is proved that underwater DC can be used to monitor the development of leakage process,and then evaluate the safe operation of water conservancy and hydropower projects;At the same time,the influence of silt layer can be controlled by underwater seismic method or underwater radar to improve the detection effect;The research results of underwater DC method are also applicable to electromagnetic method.(2)The effectiveness of AI technology for noise reduction of apparent resistivity data affected by moving water is analyzed.The results of dynamic and static water measurements are compared and analyzed,and the noise reduction effect is verified through inversion.The actual environmental water flow in the reservoir area is moving,but the current field interference caused by moving water has not been analyzed,and noise reduction has not been conducted in the current surface and underwater measurement research.The inconsistency,randomness and continuity of disturbance unsteady state caused by dynamic water environment are analyzed through experimental measurement.The simulation data set is constructed by AI technology,prior conditional noise learning and data set expansion are carried out.The depth neural network can effectively reduce the noise of dynamic water environment data,eliminate the influence of water flow,and more truly reflect the underground structure information.The application of AI technology as a tool can effectively solve dynamic water noise interference,making the actual detection more realistic.Further research can be used to suppress false anomalies and highlight useful information.(3)The slurry base material selection experiment and leakage grouting monitoring system based on electrical characteristics were established,which deepened the theoretical foundation research and expanded the application field.Grouting technology is the first choice for leakage disposal in the reservoir area because it can conduct operations such as leakage from a long distance.The complexity and concealment of leakage make it difficult to evaluate the disposal,and through the study of slurry substrate based on electrical characteristics,the space for selecting slurry substrate for different leakage situations is improved,and the plugging situation of leakage disposal can be judged on the basis of non-destructive physical property differences;Simple pressure and flow monitoring and detection methods based on resistivity change,electromagnetic wave attenuation and absorption cannot meet the needs of complex geological environment and grouting timeliness and diffusion.The The real-time collection and transmission of multi-terminal information can be realized through the Zig Bee module,which can effectively monitor the time-varying characteristics and multi-block dispersion characteristics of grouting and verify the stability of the system,and the effectiveness of the method through indoor test and field test,and form a systematic leakage detection and disposal system while expanding the geophysical application field.(4)Verified the feasibility of leakage and disposal detection in actual water conservancy and hydropower projects,and the systematic reservoir leakage detection and disposal promoted the interdisciplinary integration.The reservoir area of water conservancy and hydropower projects is easy to be affected by the surrounding geological environment,especially in areas with active tectonic movement,frequent rainstorm and mountain torrents,frequent groundwater activity and karst development.The study area of Fujiang River basin in Pingwu County is located in the Longmenshan fault zone,which is greatly affected by the Wenchuan earthquake,Lushan earthquake,landslide and mountain torrent disasters,and is typical.Combined with the engineering geology,hydrogeology and regional tectonic geological characteristics,the joint geophysical exploration of the deep part of the region,the shallow surface of the bank slope and the reservoir area underwater was carried out,which verified the feasibility of the DC electrical method for leakage detection,the effectiveness of AI noise reduction treatment and the applicability of leakage disposal measurement.It provides technical support and theoretical basis for leakage detection,safety assessment,disposal effect evaluation,accumulation body cleaning and other work of water conservancy and hydropower projects in Fujiang River basin and Sichuan basin of the same type.