Response analysis and effect evaluation of dynamic stabilization for ballasted track

Abstract

Dynamic stabilization is a process of the railway lines that are newly built must go through before it is put into operation. This study investigates the characteristics of stabilizing operation on ballasted track and proposes methods for detecting and evaluating the state of the ballast bed in an attempt to improve the operation quality. Firstly, the influence mechanism of stabilization on the migration of ballast particles and the settlement of track panel from the macro and micro perspectives through the method of visual non-contact measurement by video images were demonstrated. A three-dimensional simulation model which the first wheelset of the tamping and stabilizing vehicle - ballasted track was established using the discrete element method and multi-flexible body dynamics coupling algorithm, and the logistic mathematical model for sleeper displacement and support stiffness of ballast bed was constructed. Furthermore, an innovative non-contact method for measuring the support stiffness of ballast bed under complex scenes was proposed. Results show that the ballast particles on the slope of the ballast bed are rearranged and gradually compacted by a movement mode of “vertical as the main direction and horizontal as the auxiliary” during the stabilizing operation. As the number of stabilizing operations increases, the settlement of the track panel gradually decreases, with a maximum attenuation amplitude of 44.9%. Comprehensively, the track panel achieves reasonable load distribution after the second stabilizing operation, and achieves the best effect with the relative growth rate of the two-point stiffness being 49.5%. Significantly, this study provides key theoretical basis for the scientific stabilizing operation and evaluation of ballast bed status of railway lines that are newly built.