Study on the behavior of track formation under varying axle loads at design speed through scaled-down model testing
Study on the behavior of track formation under varying axle loads at design speed through scaled-down model testing
Understanding the dynamic behavior of railway tracks is crucial for ensuring operational safety and optimizing the design of infrastructure. This investigation presents comprehensive experimental studies conducted on a 1:3 scaled model of a railroad track to evaluate its dynamic characteristics under varying loading conditions. The scaling methodology adhered to the conservation of acceleration law. The multi-layered track formation comprises a subsoil, a subgrade of silty sand type, a blanket layer, and ballast, with layer thicknesses designed according to standard guidelines. Three railway loading combinations were investigated: 17T-240 km/h, 25T-120 km/h, and 32.5T-120 km/h, executed for one million cycles. The track formation setup was fitted with several sensors to capture the dynamic response. Experimental results demonstrate that both the stresses and accumulated settlement at each interface achieved an equilibrium state after 10,000 loading cycles. The blanket stress at the formation interface is 2.6-3.3 times less than the maximum permissible value of 300 kPa. The maximum vertical effective stress got reduced by 76-87% as it dispersed from the bottom of the ballast layer to the bottom of the subgrade for the loading combinations under consideration due to the presence of a blanket layer. Also, it was observed that the maximum formation settlement increased by 1.45 mm with the increase in the axle load from 25T to 32.5T operating at 120 km/h. The stress and settlement analysis from this study provides design guidelines for the safe operation of the railway track.
Santiram Chatterjee; Sumanta Haldar; Bappaditya Manna; Debayan Bhattacharya
11th International Conference on Physical Modelling in Geotechnics (ICPMG2026)
Special Session 1: Physical modelling – from Practice/Industry to Academia
https://doi.org/10.53243/ICPMG2026-139