GPR In The Beijing-Shanghai Expressway Disease Detection Research

The introduction of GPR in our country has not been a long time, and it has been mainly used in the field of engineering geophysics. The probe of highway by using GPR recently has been focused on the division of the layer thickness and the explanation of regional characterization of disease, and the efficiency of probing some of the obvious diseases by using GPR is not so clear. It not means that it is not suitable to probe the disease of roads by using GPR, but that the research on this field is not enough.Highway is a whole entirety added by many layers, and each layer is an artificial construction by strictly compacted. And each layer has the same texture with high uniformity. Thus, from geophysics'point of view, highway is uniform media with the same layer. The communication of electromagnetic waves in roads weakens in the form of index, in the same time, it will reflex when it meets the interface of each layer or any exception occurs. And we can have a better understanding of the internal structure of highway by doing research on reflected wave. With different kinds of diseases, we use GPR detecting these models. For that we can get typical radar map of diseases. Because the model is relatively uniform obtained under ideal environment, making information more representative, simplify complex issues to consider. Then we process the data with different processing methods by using Reflexw software and Greswin2 software respectively to get the experimental results of radar. And we also compare the results got by using different processing methods, and in this way, we get the appropriate method to process the ground radar data of highway. And we also set up disease model according to the actual situation of Beijing-Shanghai highway. According to the basic theory of electromagnetic waves and Maxwell's equations, we also have numerical simulation of the data of the highway disease by using FDTD method, and we get the theoretical response characteristics of highway disease. And meanwhile, we select the typical regional location in the test section to drill according to the results of radar inspection, and we also analyze the core sample to get the water content, porosity and layer thickness etc. And we explain the radar map according to the results to find the location of the disease, and also verify the disease by using the drilled core sample. By using this method, we can have a scientific understanding of the characteristics and manifestations of roads disease in the radar map to improve the accuracy and ability of probing highway disease by using GPR...