Study On GPR Model Test And Signal Feature Recognition Of Underground Pipeline

As the lifeline of the city,underground pipeline is responsible for many important functions of the whole city operation,but its aging pipeline,incomplete construction information and other factors have caused many underground civil engineering accidents,so it is necessary to detect underground pipeline before the construction of underground engineering.GPR is widely used in the detection of underground pipelines because of its large detection range,high accuracy,simple operation and strong resolution.GPR detection can make more accurate and reliable judgment on the location and direction of underground pipeline,but at present,the radar echo signal processing technology of underground pipeline is not mature,and the identification method of pipeline diameter is also one-sided.Based on this,GPR is used to detect underground pipeline,and the signal processing and feature recognition of target image are studied.In this paper,the signal processing method and pipeline identification technology are studied by simulated radar echo map of underground pipeline,and then verified by model test and engineering measurement,so as to systematically and deeply study the practical value of GPR in underground pipeline detection.The main research contents and results are as follows:(1)The radar echo map of the simulation underground pipeline and the pipeline test detection map show that the echo signal characteristics of the underground pipeline have hyperbolic characteristics.Through MATLAB language,the echo signal is processed by many kinds of filtering and edge extraction methods.Filtering can suppress the clutter in the image,and edge detection can also extract the edge signal of the target effectively.(2)The radar echo image analysis of simulation and test shows that the characteristics of pipeline material,buried depth and direction can be directly identified from the image.Three calculation methods are used for the identification of pipe diameter.The simulation and test data show that the three methods are practical and feasible,but each has its own advantages and disadvantages and one sidedness,and the three-point circle determination method has the best effect.In order to make the image processing more convenient and simple,a GUI quick processing interface is established by integrating the reading,graying,filtering,edge detection,pipe diameter identification,saving and exiting of the radar echo image of underground pipeline.(3)Through the underground pipeline detection test under various working conditions,it is shown that GPR can accurately detect and analyze the complex pipeline layout,such as parallel,cross,shelter,etc.At the same time,the application of GPR in the actual engineering detection and the analysis of the result image further verify the practical value of GPR in the detection of underground pipelines.The GUI program developed in this paper is applied tothe image obtained from the experiment and the actual measurement.The results show that it can process the result image and identify the pipeline features better,which shows the practicability of the program.In this paper,the signal processing and feature recognition of pipeline radar echo are studied through the detection of underground pipeline by GPR,and the methods of signal processing and pipeline feature recognition are summarized,which are proved to be feasible and practical.It shows that GPR has important practical value for the actual underground pipeline detection engineering.