Prediction of future railway ballast tamping requirements
C. Charoenwong, David P. Connolly, Tengfei Wang, Kaiwen Liu, Pedro Alves Costa, A. Romero, P. Galvín
Abstract
This paper presents a numerical framework for predicting future railway ballast tamping requirements under varying operational and environmental conditions. The approach integrates an empirical ballast settlement model, derived from large-scale laboratory tests, into a dynamic track-ground interaction framework using the 2.5D Finite Element Method. It is capable of capturing differential settlement and track geometry deterioration considering different types of ballast fouling material, varying levels of ballast moisture content, train speed and traffic volume. Track geometry profiles are updated iteratively after each axle passage, enabling condition-based assessment of future tamping needs. First the model is calibrated using historical track geometry data from an operational railway line. Following calibration, an analysis is performed to study the effect of different moisture levels and types of ballast fouling material (sand, coal and abrasion-induced fines) on track geometry degradation and ultimately future tamping requirements. Next, to understand the effect of different possible track renewal strategies on future tamping requirements, the effects of increasing the rail section and adding under sleeper pads are compared. Results indicate that moisture content, speed, and traffic volume are dominant factors governing tamping frequency. While the type of fouling material and the proposed renewal strategies have a comparatively moderate effect, their influence remains non-negligible. These findings highlight the importance of maintaining adequate track drainage and implementing measures to control the type and extent of ballast fouling.