Field performance to mitigate impact vibration at railway bridge ends using soft baseplates

The current state of bridge ends and transition zones in railway industry around the world calls for a new and innovative way of design and utilisation of essential components that can automatically combat large dynamic settlements at the stiffness interface. Railway bridge approaches or bridge ends often suffer from a combination of dynamic wheel/rail interaction and poor formation compaction due to construction difficulties at the location, resulting in an initial short-wavelength track settlement at the first few sleeper bays near the bridge over a short period under revenue services. This settlement then further induces impact loading that aggravates differential track settlements. The differential settlement problem at these locations has incurred expensive and frequent maintenance at the areas, causing downtime or restricted railway operation; and importantly more frequent maintenance, which is costly and time-consuming. A collaborative research investigating field performance of the novel component to soften rail elasticity has been carried out. This research demonstrates an application of special soft baseplates and fastening systems to isolate the coupling dynamic actions transferring between transom steel bridge and the ballasted track at the bridge ends. Field measurements were conducted before and after the installation. The results provide strong evidence that the baseplates can filter dynamic impact content from the aggressive loading conditions and provide longer-wavelength load redistribution over railway track infrastructure. This paper highlights field performance of railway bridge ends, which have been upgraded by the soft baseplates and fastenings. It shows that lesser vibration contents are transferred to ballast and granular layers, reducing the risk of differential settlement and ballast dilation.