Vibration and performance of a subway track system based on the third y K Cheung lecture, Hong Kong, 2009

Abstract

This paper presents an integrated study of a subway track system with emphasis on the effects of rail pads on the vibration and performance of the system. The study covers analytical, numerical and experimental investigations as well as field measurements of a floating slab track system in an urban rapid transit system. Experimental tests of rail pads are conducted to determine the dynamic characteristics of several types of rail pads. To account for the increase in pad stiffness due to ageing, an energy-based predictive deterioration model is proposed. Field measurements of pad deformations under actual train operations were carried out over three years to validate the proposed model. Rainflow analysis is performed to compute the equivalent ranges and cycle counts to account for the non-periodicity of actual vibrations of rail pads on site. Finite element method is used in both the back analysis for roughness determination and forward analysis for response prediction.