طراحي و ساخت پيكربندي اندازه‌گيري شاخص اتلاف جاي‌گذاري جهت ارزيابي عملكرد ديناميكي روسازي راه‌آهن در مناطق حساس به ارتعاش

Railway noise an‎d vibration , Empirical prediction model , inser‎tion loss , Track resilience , Transfer function

Design an‎d implementation of the inser‎tion loss measurement setup for dynamic eva‎luation of railway superstructure in vibration-sensitive areas

مهندسي راه آهن و برنامه ريزي حمل و نقل

Existing empirical prediction models, due to their reliance on simplified track superstructure representations, cannot account for all parameters influencing track stiffness an‎d damping, thus limiting their utility in vibration-based railway line design. This study addresses this limitation by introducing a novel empirical prediction model that directly integrates a Track inser‎tion Loss Index into vibration forecasts. This index is formulated from extensive laboratory measurements encompassing 189 distinct track superstructure configurations, revealing that vibration attenuation is significantly dependent on the floating slab condition, fastening system stiffness, an‎d elastomer mechanical properties. Notably, the elasticity level of the fastening system was found to have twice the impact on the inser‎tion Loss Index compared to that of the elastomer. The proposed model was applied to design a railway line in close proximity to a 1000-year-old historical site. Analysis of the inser‎tion Loss Index demonstrated that appropriate selec‎tion of superstructure stiffness parameters can yield substantial vibration level reductions (up to 40 decibels), enabling compliance with stringent vibration criteria for sensitive structures. Furthermore, the new model provides superior prediction accuracy (approximately 5 decibels higher) compared to most existing empirical models an‎d effectively identifies potential interference between track tuning frequencies an‎d the natural frequencies of nearby structures. In conclusion, the incorporation of the inser‎tion Loss Index into the proposed empirical model equips engineers with a robust tool for the precise assessment an‎d optimization of key track parameters to mitigate vibrations from the initial planning stages of railway development.

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