Ground Penetrating Radar(GPR) Application In Urban Engineering Survey Research

Underground voids,pipelines and existing buildings are the main targets of urban engineering survey,and the accurate detection of them can provide guarantee for the construction of urban projects.And ground penetrating radar(GPR)as a new urban engineering geophysical prospecting method,has the characters of nondestructive,super-speed,high precision,high resolution and low cost etc.,now has became an important part of urban engineering investigation.Therefore,this paper focuses on the application of ground penetrating radar in urban engineering survey,the work includes the following several points.(1)Expounding the theoretical foundation and working principle of GPR,summarizing the application of GPR,discussing the ground-penetrating radar data processing,data imaging methods and data interpretation methods.(2)Expounding the finite difference time domain method(FDTD)theory,in view of the urban geological problems in engineering investigation,according to.the actual situation,by setting different abnormal body model and carry on forward modeling,we analysis the response regularity and characteristics of electromagnetic wave.(3)On the basis of the GPR data from the field,and combining with the result of forward modeling,we explain and analyze the GPR of difFerent geologic abnormal body imaging effect and the recognition accuracy.Through the above works,this paper has achieved the following points:(1)Through the forward simulation of GPR,the forward modeling of cavity and pipeline is realized,and the results of forward modeling can provide a reference for the accurate identification of abnormal body.(2)Taking engineering as an example,city roads are summarized at the bottom of the hole,imperfect,pipeline and concealed pier foundation of GPR image characteristics and identification methods.Through the practical detection,demonstrates the nondestructive detection of GPR in the city is effective.