Abstract
The paper presents the results of a field-based investigation of the vibrodynamic response of railway track superstructure elements and subgrade under the action of rolling stock in real operating conditions. Vertical vibrations were recorded in the shoulder zone of a stable railway embankment during the passage of a VL-80 electric locomotive at different train speeds. To assess the influence of speed on vibration parameters, analyses were performed in both time and frequency domains, including the determination of peak accelerations, root mean square (RMS) values, dominant frequencies, and spectral energy characteristics. The aim of this study is to establish quantitative relationships between train speed and vibration response parameters of the railway subgrade under real operating conditions. Stable relationships between vibration parameters and train speed were identified, reflecting systematic changes in the dynamic state of the “track superstructure–subgrade” system under increasing operational loading. The scientific novelty of the study lies in the in-situ experimental identification of speed-dependent vibration characteristics of the subgrade shoulder and in the integration of time- and frequency-domain parameters for vibration-based condition assessment under real traffic conditions. The obtained experimental data can be applied for vibration-based condition assessment of railway embankments. The proposed approach is aimed at developing practical monitoring methods for early detection of anomalies, improving maintenance planning efficiency, and enhancing the management of railway infrastructure condition.