The Modeling Research On GPR Of Pavement Crack Disease

As widespread in asphalt concrete pavement of disease damage,cracks have received increasing attention various road maintenance sector.While traditional methods can't detect its early form,Ground Penetrating Radar(GPR),as a new road detection technology,it has now been more and more widely applied.It's a non-destructive testing technology with continuous and fast,high efficiency and no damage to the road,high resolution and non-affected by the weather's advantages.At present,the identification and resolution of ground penetrating radar image is still in a relative low degree.Human factors accounted for a very large proportion.Through the pavement Structure disease forward modeling analysis,we can give insight into the laws of geological radar reflection cross-sectional view of the highway disease,and thereby improve the reflected image interpretation accuracy and precision will help to further promote the effective application of GPR technology and improve.After years of development the Finite Difference Time Domain(FDTD)method has become a very maturely numerical simulation of the electromagnetic method.Its application nearly covers all the current electromagnetic fields.Ground penetrating radar technology,as an important outcome of the transient electromagnetic theory,works in line with the theory of electromagnetism.Further studies of forward technology can also effectively promote the application and development of ground penetrating radar technology.The traditional uniform medium model can't reflect the real radar wave propagation in the underground space,this article is based on the random medium model,and analysis the current disease early cracks in asphalt concrete pavement layer,but also,compare with the pavement cracks diseases collected in the field results.The contents of this paper are as follows:(1)Detailing the crack disease existing in the road and analysis its formation mechanism and basic characteristics,as well as an overview of the commonly used detection methods and their advantages and disadvantages;Briefly introduce the GPR's composition and working principle,analysis its impact of relevant parameters on forward modeling;(2)Establishing the stochastic medium model of electromagnetic waves by using theory related to elastic waves and analyzing its radar waveform features;Compare the results of the CAS radar test results and the simulation model of random media performed to verify the accuracy of the results of the random medium model;(3)Establish the forward modeling of two-dimensional space by the method described above under the random medium model,crack disease research at different radar center frequency and radar cross-sectional view and waveform under different dielectric constant,and also discussed its different measuring positions and the size and shape of the waveform,and summarizes the characteristics of these images.(4)Compare the results of field data collection and the forward modeling results to verify the accuracy of forward modeling results.