A Train-Mounted GPR System for Operating Railway Tunnel Inspection

Abstract

With the increasing number and aging of railway tunnels, regular inspection will be an important means to ensure the safety for operation railways. A train-mounted ground penetrating radar system with cores of air-coupled antennas and shared time-window model has been developed to allow for long-distance and fast inspection of tunnels. The system consists of 6 groups of air-coupled antennas with center frequency of 300 MHz. The distance between antenna and lining is 0.5-4.0 m, the scanning rate of the system is 976 scans/Sec and the detection depth of the GPR can reach to 2.5 m. Under the theoretical design, the maximum speed of train can reach 70.27 km/h with a scan interval of 0.02 m. The test results on Shenyang-Dandong railway passenger dedicated line show that the system can identify the thickness of lining, the void and the backfill state behind lining.