Designing Railway Vibrations Isolation Barriers Using Frequency-Domain Numerical Modeling

Abstract

The article presents the results of numerical modeling assessing the effectiveness of vibration barriers for protecting rail transport infrastructure elements, specifically tram tracks and subway tunnels, from vibrational impact. The study examines three types of structures: horizontal, vertical, and combined barriers made from stone wool, expanded polystyrene (EPS), and extruded polystyrene (XPS). The methodology is based on solving the elastodynamic equations in the frequency domain using a finite-difference scheme that accounts for the free surface and utilizes perfectly matched layers (PMLs). The results indicated that horizontal barriers are most effective when using XPS (up to 70% vibration reduction), but are susceptible to resonances at specific geometric dimensions. Vertical constructions exhibited a lower propensity for resonance phenomena, with an EPS vibration barrier demonstrating the potential for vibration reduction of up to 90%. Combined systems yielded the best performance, providing broadband protection (1–250 Hz) with an effectiveness of up to 97%. Key factors influencing effectiveness were identified as: material properties (durability, damping characteristics of stone wool, stiffness of XPS), geometry (width exceeding 0.6 m, depth exceeding 3 m), and frequency range. Practical recommendations include the use of horizontal barriers for high-frequency vibrations, vertical barriers for low-frequency vibrations, and combined structures for vibration protection across a broad frequency spectrum. The research opens prospects for the development of multilayered and nonstandard geometric solutions, as well as for conducting field tests.