APPLICATION OF GROUND PENETRATING RADAR IN SUBGRADE DEFECT DETECTION ON DA-QIN HEAVY HAUL RAILWAY

Based on the experiment of Da-Qin Heavy Haul Railway, introduce the principle and scheme of the application of ground penetrating radar in subgrade defect detection. The paper discusses the application of RIS ground penetrating radar of Italy, which have two aerial combined and one single-frequency. The two combined aerial can work simultaneously, which is called the technology of multifrequency in aerial. The technology solves the contradiction in present situation between the depth of detection and the resolution power of the detection, improving the precision and the efficiency of the detection. Kinds of the aerial transmitting the signal and receiving intercross, which augment the angle of the radar, has the best effect in the complex objects which very close to each other in horizontal or lap over. By the way of processing data and analysis the result of the experiment, acquire the model characteristic of the image of usual defect on heavy haul railway subgrade, such as frost boiling and mud pumping, subsidence, ballasts hole, pipeline and so on. This paper conclude that ground penetrating radar has the specialty of speedy, nondestructive and little impact in the operating of the train during the process of subgrade defect detection; the result can show many informations of the subgrade defect, such as location, depth, scope, severity and so on. These informations can be used to guide the maintenance exactly, which can increase the efficiency of the detection and maintenance in significant measure. The application of ground penetrating radar in subgrade defect detection should be popularized to practice extensively.