Loading...

Investigation of Train-Induced Vibration Reduction using Wave Barrier-Filled Trenches

Aghaei, Mohammad Pouria | 2025

88 Viewed
  1. Type of Document: M.Sc. Thesis
  2. Language: Farsi
  3. Document No: 58869 (09)
  4. University: Sharif University of Technology
  5. Department: Civil Engineering
  6. Advisor(s): Ahmadi, Mohammad Mehdi
  7. Abstract:
  8. The rapid expansion of urban and intercity railway networks in recent years has made the control of train-induced ground vibrations a critical issue in infrastructure design and environmental comfort. These vibrations, which mainly propagate as Rayleigh surface waves in shallow soil layers, can cause discomfort to residents, malfunction of sensitive equipment, and even long-term structural damage to nearby buildings. Among various vibration-mitigation techniques, the use of wave-barrier trenches is recognized as one of the most practical and effective solutions. The present study aims to numerically investigate the efficiency of infilled wave barriers using innovative materials such as sand–rubber mixtures (SRM) and seismic metamaterials (Metabarriers) for the reduction of vibrations induced by moving trains. A two-dimensional numerical model was developed in FLAC2D software to simulate the dynamic behavior of the soil–structure system under harmonic loading applied at the ground surface. The computational domain included absorbing boundaries (PML) to prevent wave reflection, and the dynamic properties of the soil and infill materials were assigned based on experimental and field data from reliable sources. The model was validated in three stages against benchmark studies to ensure the accuracy of wave amplitude, phase, and spectral response. After successful validation, a comprehensive parametric analysis was performed to evaluate the influence of trench depth, width, distance from the vibration source, and foundation type on vibration attenuation. The results showed that the presence of a trench—particularly those filled with SRM significantly reduces ground-vibration amplitudes behind the barrier. Increasing the normalized trench depth up to about 0.7λ provided the most effective attenuation, beyond which the improvement became marginal. Among the investigated materials, the SRM70 mixture (70% rubber) demonstrated the highest damping and energy-absorption capacity, achieving a performance level only about 15% lower than that of an open trench. Moreover, the metamaterial configurations created a frequency stop band in which Rayleigh waves could not propagate, effectively acting as a seismic-wave filter within the soil medium. In conclusion, the study confirms that using lightweight, high-damping materials such as SRM and Geofoam, combined with optimized geometric and positional design of trenches, can substantially mitigate train-induced vibrations. Furthermore, the integration of seismic metamaterials into geotechnical systems introduces a promising direction for the design of next-generation vibration-isolation systems in rail and underground infrastructures
  9. Keywords:
  10. Amplitude Reduction ; FLAC2d Software ; Sand–Rubber Mixture ; Seismic Metamaterial ; Train-Induced Vibrations ; Vibration Reduction Methods

 Digital Object List

 Bookmark

No TOC