Discussion of 'Deformation of Coal Fouled Ballast Stabilized with Geogrid under Cyclic Load' by Buddhima Indraratna, Ngoc Trung Nqo, and Cholachat Ruiikiatkamiorn

摘要

The authors demonstrated through a series of experiments undertaken in a modified novel laboratory track simulation apparatus with geogrid- and nongeogrid-reinforced coal-contaminated ballast containing varying degrees of coal contamination measured by the void contamination index (VCI) and subjected to cyclic loading that geogrid-reinforced ballast displays a superior behavior to unrein-forced ballast and further that a geogrid-reinforced ballast bed can possibly sustain a VCI of 40% before track maintenance is warranted. This optimum VCI of 40% was determined through the evaluation of the results of vertical and lateral deformations measured over 500,000 cycles of cyclic loading applied to 10 levels of VCI varying from 0 to 70% on both geogrid-reinforced and nongeogrid-reinforced ballast.