Forward Simulation Of Ground Penetration Radar Based On GprMax For Roadbed Detection

In the past 20 years or so,China's national economy has been rapidly developed,and various infrastructure constructions have also achieved significant results,among which highway construction has experienced rapid development.However,it also puts forward higher requirements for the engineering quality of highway traffic construction.The traditional method for the detection of highway subgrade has not met the needs of largescale,short-term construction time,high precision,and non-destructive road engineering.Therefore,ground penetrating radar technology with high efficiency,high accuracy,flexibility,and no damage has been promoted.This paper describes the working principle,equipment composition,measurement methods,applicability evaluation of ground penetrating radar,and the use of ground penetrating radar in the detection of subgrade.It also explains the main factors affecting the depth and resolution of the ground penetrating radar,and expounds the FDTD algorithm.Basic theory,starting from Maxwell's equations,studies the numerical theory of FDTD method.From the point of difference calculation,iterative,absorbing boundary conditions,meshing of difference equations,determination of conformal mesh medium parameters,and setting of excitation sources are discussed.This paper introduced the road road diseases and road damage caused by common roads in the project,analyzed its characteristics,adjusted the parameters and carried out several numerical simulations.Through the comparison experiments,the image laws of the subgrade diseases under different conditions were obtained and actually The ground penetrating radar data in the project is compared and analyzed,and the similarities and differences between them are compared to explain the reason.Finally,the paper concludes that the forward modeling of roadbed diseases can have a strong reference for practical projects.The main types are as follows:(1)Based on the finite-difference time-domain method,a three-layer highway model was established.The gprMax electromagnetic simulation software was used to simulate forward modeling of each layer of highway and the propagation of electromagnetic waves in the model was explored.(2)Researched the common roadbed diseases,summarized the characteristics of the disease,established a disease model after simplification,studied the propagation characteristics of electromagnetic waves in different roadbed diseases and imaging conditions of reflected waves by changing different parameters,analyzed and summarized the forward modeling.Simulation of the results of the law,respectively,numerical simulation of subgrade voids under different conditions,under different conditions of the subgrade hydrous zone,under different conditions of subgrade soft soil,subgrade is not dense,the ancient landslide sliding surface in the roadbed.(3)Ground penetrating radar data from 3 actual roads were used to compare with the forward modeling results to verify the validity and guiding significance of the forward modeling results and to compare and analyze the differences between the results.