ABSTRACT
The relationship between railway track-bed stresses and speed is essential when performing track foundation design. Current approaches to describe this relationship are typically empirical and multiply the static track response by a dynamic amplification factor to account for speed effects. This paper develops an alternative method for dynamic amplification factor generation instead of numerical simulation. A vehicle–track dynamics model is presented, capable of simulating the subgrade dynamics considering random track irregularities. First, samples of irregularity are generated based on a mean vertical track profile power spectral density. A range of train speeds and track-spectrum cumulative probabilities are computed using the numerical model before analyzing the resultant surface stresses. The resulting dynamic amplification factors follow a Gumbel distribution. Data normalization is performed before developing a bespoke dynamic amplification function. Based on speed, track-spectrum cumulative probability, and p-values, the proposed model yields dynamic amplification predictions within 5% of the simulated values.
Acknowledgments
The study was supported by the National Natural Science Foundation of China (52078435), the Natural Science Foundation of Sichuan Province (2023NSFSC0391), the Royal Society (IEC\NSFC211306 – International Exchanges 2021 Cost Share), the Key Laboratory of Mechanical Behavior Evolution and Control of Traffic Engineering Structures in Hebei (SZ2022-03), and the 111 Project (B21011).
Disclosure statement
No potential conflict of interest was reported by the author(s).