Performance analysis of subgrade in asphaltic rail track design and Indonesia’s existing ballasted track

Abstract Due to subgrade-related concerns, the performance of Indonesia’s ballasted track continues to be significant impediments for the Indonesian railway stakeholders’ intention to increase the speed of passenger train operations. This study aims to examine the vertical compressive stress in the subgrade of Indonesia’s ballasted track and two asphaltic rail track designs, asphaltic overlayment and asphaltic underlayment, under various cyclic loading conditions based on three different train speeds, 120 (low speed), 240 (medium speed), and 360 kph (high speed). The AC layer thicknesses for each asphaltic rail track design are as follows: 0.1, 0.2, 0.3, and 0.4 m for asphaltic underlayment, and 0.075, 0.15, 0.225, and 0.3 m for asphaltic overlayment. 2D finite element models and simulations were used to capture and predict the subgrade’s vertical compressive stress performance. The most obvious finding to emerge from this study is that the asphaltic overlayment track has a greater capacity for transmitting and decreasing stresses from the top structure to subgrade layer than the asphaltic underlayment track and the Indonesia’ ballasted track, respectively. This research can shed light on the prospective application of asphaltic rail track to the Indonesian rail network for the faster passenger trains operation.