Experimental Study On Detection Of Water Supply Pipeline Leakage And Automatic Identification System By The GPR

Water supply network leakage is a hot issue in the global water supply industry,Water supply pipeline leakage not only wastes water resources,but also threatens urban construction facilities,affects traffic,and destroys normal urban order.Ground penetrating radar(GPR)has the characteristics of nondestructive,fast and efficient in detecting leakage of water supply pipeline.But due to the complexity of the water supply pipeline space layout,and the steady growth of urban underground infrastructure,Identifying leakage in water supply pipeline requires a high level of expertise on the part of operators,these aspects greatly increase the difficulty of GPR data analysis and interpretation in detecting pipeline leakage,reducing the potential of the promotion and application of the GPR,increasing the demand for high-quality personnel.Therefore it is great practical significance to study the nondestructive detection of water supply pipeline leakage by GPR and realize automatic identification and real-time alarm of water supply pipeline leakage.This topic is derived from the key research and development plan of the 13 th Five-Year National Ministry of Science and Technology,“Technology and Application of Monitoring and Control of Leakage in Urban Water Supply Pipeline Network”(2016YFC0400600),Sub-topic “Optimization Maintenance Model and Technology Research of Water Supply Pipeline Network”(2016YFC0400605).Its main research contents and results are as follows:(1)A physical model for nondestructive detection of water supply pipeline leakage by GPR is established.When the pipeline is not leaked,when the GPR detects along the parallel and vertical direction to the pipeline.In the wave amplitude value graph of X and Y survey lines,the pipeline presents a straight line shape and a double curve shape.(2)When the pipeline is leaking,when the GPR detects along the parallel and vertical direction to the pipeline.In the wave amplitude value graph of X and Y survey lines,the pipeline still presents a straight line shape and a double curve shape,and the pipeline position moves down compared with that in the case of no leakage.In the Y9 survey line and the X11 survey line,the absolute value of the wave amplitude value increases below the pipe.(3)A mathematical model for automatic identification of pipeline leakage is built.When the pipeline is leaking,in the wave amplitude value graph of Y survey line,the slope between the maximum absolute value of wave amplitude value in the adjacent channel internal at the top of the pipeline is 0.The area where the absolute value of the wave amplitude value increases below the pipe.the gain makes it exceed beyond the range of the wave amplitude value range,while the wave amplitude value in other regions is still within the range of the wave amplitude value.Develop programs to identify pipes and pipe leaks.(4)Verifing the validity of the pipeline leakage model of GPR nondestructive testing.The sand in the test groove is excavated after the test.According to the wave amplitude value in the sand plane of each layer,A cross-section of the wave amplitude value of the plane is established,Calculating the contour size of wet sand in the figure and comparing it with the actual contour size of wet sand in the plane of each layer of sand.so as to verify the effectiveness of GPR in nondestructive detection of pipeline leakage.