An investigation into vibration transmission patterns within metro turnout areas utilizing the structural sound intensity method

Urban rail transit turnout areas are notorious for inducing elevated environmental vibrations due to the complex interactions between wheels, rails, and supporting infrastructure. This paper establishes a comprehensive vehicle-track-tunnel-soil coupled dynamic model of a train traversing a turnout region. The intricate vibration transmission mechanisms within the turnout are explored through numerical simulation and visualization of vibration energy flow pathways. The structural sound intensity method facilitates the directional characterization of both transverse and longitudinal elastic waves emanating from the wheel-rail contact zone. Results reveal distinct propagation patterns between the switch panel and crossing panel, with more pronounced low-frequency energy backflow occurring in the switch panel. The transverse wave is found to dominate the elevated lateral vibrations observed along the tunnel walls. Frequency domain analysis maps the variation in energy flow directionality across one-third octave bands. The findings align closely with field measurement outcomes, validating the capacity of the approach to identify vibration "hot spots." Overall, this research enhances the theoretical comprehension of the complex interplay between diverse factors influencing turnout vibration transmission dynamics. The visualization technique proves instrumental in elucidating the critical mechanisms underlying the exacerbated environmental impact within these structurally intricate domains. Practical insights are distilled regarding turnout design strategies, vibration monitoring, and control methodologies to facilitate the mitigation of detrimental vibration effects.