The Applications Of Ground Enetrating Radar In Underground Construction

With the expanding of China’s transportation network, ground penetrating radar technique is widely used in the quality detection of railway and highway tunnel. This is an efficient, advanced and lossless method which is capable of continuous scanning of tunnel lining and can generate intuitive detection images. However, there are still some aspects which deserve further research for improvement, e.g. the accuracy of detection and image analysis.In this paper, starting from the working principle of ground penetrating radar in particular the electromagnetic wave propagation characteristics of radar, the wave is reflected at the interface of different medias and accompanied by abnormalities. Using the flume model testing to explore the onset position of radar waves and the manifestations of the reinforced steel shows on the radar image,which has provided the basement of the interface determination. The visualization features of different types of tunnel lining in radar images were summarized through the study on the tunnel lining model, specially for the identifications for the tunnel lining reinforced steel in single or double layer,the arch behind reinforced concrete,and the void in different forms which have guiding significance in the engineering detection department.Real engineering examples were combined to compare with the testing results and the differences between the test and the actual engineering examples were found. There are still limitations with this test but it is instructive to the future work.