Research And Application Of Ground Penetrating Radar In Large Depth Detection

GPR has been applied more and more in the traditional geological prospecting fields such as engineering geology,hydrogeology and geological hazards,as well as in the structural detection fields like tunnels,bridges,dams and municipal roads,and the requirements for GPR methods and technologies are getting higher and higher.On the one hand,in the field of geological exploration,tunnel advance prediction,municipal road disease detection and other detection needs to improve the detection depth of geological radar.In order to improve the detection depth of geological radar,the theoretical research on the excitation,propagation and reception of electromagnetic wave is carried out in this paper.Combined with theoretical research and numerical simulation,the research of electromagnetic wave reflection and transmission,radiation range and polarization direction,loss and attenuation,transverse and longitudinal resolution in various media has been analyzed.A layered medium model,a point(tube)medium model and a hollow medium model are established and their wave field response characteristics are studied.Combined with the numerical simulation and the measured data,the measured results of different dielectric conductivity,different antenna center frequency,different GPR transmission power and different stack times are analyzed.The results show that the detection depth of GPR is directly related to the dielectric conductivity of the medium,the frequency of the antenna center,the dielectric constant under the condition of low conductivity,the maximum transmitting power,the sensitivity and the dynamic range of the system.Based on the previous research results,the karst exploration in a certain area has been systematically studied,and the ideal exploration depth and resolution have been obtained.