Study on the Influence Mechanism of Metro-Induced Vibrations on Adjacent Tunnels and Vibration Isolation Measures

To investigate the effectiveness of vibration mitigation and isolation measures for adjacent tunnels in a metro-induced vibration environment, this study employed a similarity theory-based scaled model test at a ratio of 1:15. The prototype was the Guangzhou 500 kV Suixi-Chuting power transmission tunnel project. The experimental methodology was designed to simulate the vibration impact on adjacent tunnels from metro loading and to evaluate the performance of various countermeasures. The vibration response mechanisms induced by different mitigation materials were analyzed. The results demonstrate the theoretical feasibility of the overall design of the scaled model test, which accurately reproduces the vibration influence on adjacent tunnels from metro loads. Both Expanded Polystyrene (EPS) and rubber particles were found to provide measurable vibration reduction. However, the attenuation achieved by EPS was significantly greater than that of rubber particles, indicating the superior performance of EPS as a vibration isolation material. Furthermore, the isolation mechanisms of both materials were discussed based on observations of their behavioral changes during the vibration isolation process. The findings of this study offer valuable insights and a reference for selecting appropriate vibration mitigation materials in practical engineering applications.