The Application Of GPR In Road Engineering And Research On Data Analysis Of GPR

In highway construction, the use of Ground Penetrating Radar (GPR) has become extensive. GPR is an effective non-destructive test tool to detect buried targets, and it detects buried targets via the discontinuity of dielectric. It is a method of high frequency electromagnetic measurements. Resembling sounding radar, GPR uses transmitting antenna that emits high frequency electromagnetic wave, which is in a broadband pulses form, in the buried targets direction. The electromagnetic wave will create reflection, when passing the discontinuity of dielectric, and be received by receiving antenna. Through the analysis of the transmit character of electromagnetic wave in time and space, the information about the spatial location, scale, physical properties etc., of the buried targets will be obtained. GPR has a lot of virtues, such as rapid and continuous detection, simple and convenient operation, high resolution, nondestructive detection etc, so it has been frequently used in the construction fields of highway, bridge, tunnel etc.The scope of the use of GPR has been expanded in the highway construction nowadays and more research has been put on it. The applications of GPR mainly focus on the detection of the spatial location, scale, physical properties of the buried targets. When processing and interpreting the data, we often assume that the surrounding dielectric of the buried targets is homogeneous. However, when GPR is actually used to the road construction, such as the supporting base, lining, roadway, pavement etc, the dielectric is an inhomogeneous medium which is composed by various substances. Therefore the electromagnetic properties of these substances are determined by such factors as physical properties and structure of the composition, porosity, water content and temperature etc. In most cases, these factors are not all congruence within a certain scale. As a result, the natural substances exhibit heterogeneity, and the propagation character of the electromagnetic wave will change to a certain degree when the electromagnetic wave passes through them. When the medium is heterogeneity, the electromagnetic wave will produce electromagnetic scattering and diffraction on the uneven particle surface, and the propagation of the electromagnetic wave will occur distortions, creating geology"delta noise". As a result, the character absorbing electromagnetic wave will also change to some degree. It can be seen that the use of fixed filter to eliminate noise on GPR is unreasonable.Based on the analysis of the effects of using fixed filter, which is often adopted in...