Spectrum analysis of railroad track with hanging tie problem

Hanging tie is a railroad track distress when voids have been developed beneath the ties due to uneven ballast settlement and improper maintenance practice. It, in return, will lead to an increase in dynamic impact loading on the top of the ballast and therefore further deteriorate the track structure. It is often difficult to identify this problem in an efficient and nondestructive manner. This paper proposed a non-destructive and fast screening method to identify hanging tie problem. A dynamic track model capable of simulating moving load and detailed tie supporting conditions is first introduced and then utilized to construct rail deflection spectrums for tracks with different supporting conditions. Case studies of different configurations of ties will be employed. Conclusions will be drawn and important findings will be highlighted in the end.