Study on vibration isolation performance of rubberized concrete piles for tunnel in rail transit

Vibration generated by train operations inevitably exerts negative impacts on the surrounding environment. As a commonly adopted vibration control measure along the transmission path, vibration isolation piles have been widely implemented. This study, based on traditional vibration isolation pile technology, proposes for the first time an improved structural design combining rubberized concrete and a top cap beam as a comprehensive solution aimed at enhancing vibration isolation performance. Furthermore, scientific modeling is conducted based on model tests, and the vibration isolation performance of various pile types in single-row and triple-row configurations is subsequently investigated. The results indicate the following: 1. Ground surface vibration behind the piles attenuates in a “wave-like” pattern with increasing distance. Installation of different types of single-row piles effectively reduces vibration levels behind the piles; however, a vibration amplification effect is observed in front of the piles. 2. Among triple-row configurations, the hexagonal arrangement demonstrates superior vibration isolation performance behind the piles compared to the square arrangement. 3. Compared to conventional concrete vibration isolation piles, the incorporation of rubber significantly enhances the vibration isolation effectiveness behind the piles for both single-row and hexagonal triple-row configurations. 4. Improved vibration isolation piles exhibit excellent performance in mitigating vibrations both in front of and behind the piles. Moreover, their vibration isolation capacity is positively correlated with the depth of the top cap beam, indicating promising potential for practical applications.