هيوا ربيعي مطمئن

In recent years, the proliferation of urban rail transit infrastructure has presented a significant engineering challenge regarding ground-borne vibrations induced by rolling stock movements. These vibrations not only cause structural deterioration to adjacent buildings but also significantly compromise the living conditions of nearby residents. Among various vibration mitigation measures, the track fastening system for slab track, functioning as the primary isolation interface, plays a pivotal role in vibration attenuation an‎d transmission reduction. Given the critical nature of this track component an‎d the imperative to optimize its performance in vibration mitigation, this research investigates the influence of track fastening system parameters on vibration reduction in operational metro systems. To achieve the research objectives, a comprehensive numerical model based on Tehran Metro Line 6 track specifications was developed. The numerical model architecture comprised two principal sub-models: The first sub-model was engineered for dynamic load generation, where the track structure was modeled using a 2D model along the longitudinal axis, an‎d the fastening assembly was represented through a spring-damper mechanism. The second sub-model was developed to analyze wave propagation characteristics through precise tunnel cross-section modeling an‎d application of dynamic loads derived from the first sub-model. For model validation, extensive in-situ measurements were conducted on Tehran Metro Line 6. The validation process demonstrated satisfactory correlation between field measurements an‎d computational results. Following validation, five distinct fastening systems, representing diverse mechanical properties, were eva‎luated. Results showed that rigid fastening systems, compared to resilient systems, transmit dynamic forces with greater intensity, leading to a 10% increase in applied forces an‎d 6% increase in RMS acceleration. Conversely, resilient systems like Vanguard demonstrated superior performance with a 37% reduction in fastening forces an‎d a 44% reduction in peak acceleration. Parametric analysis revealed that the optimal design range for damping is approximately 10 kN.s/m an‎d for stiffness is 5-12 kN/mm, resulting in about 63% reduction in vibration levels. These findings can serve as practical guidelines in designing vibration control systems for metro infrastructure, particularly in sensitive urban areas.

سيستم اتصالات روسازي صلب , كاهش ارتعاشات , مترو , اندازه‌گيري‌هاي ميداني

Rigid Track Fastening System , Vibration Mitigation , Metro System , In-situ Measurements

Hiva Rabiee Motmaen

Dr. J. Sadeghi, Dr. A. Toloukian