Analysis On The Transfer Law Of Braking Force In CrtsⅡ Ballastless Track Slab On Bridge

With the rapid development of high-speed railway all over the world, it has become a trend for countries to use ballastless track on these railways. Among them, the slab ballastless track is most often used in our country's some constructed and under construction passenger dedicated line.As to the CRTSâ…¡ballastless track slab on bridges, the main components, that are the rail,rail slabs and base plates, are longitudinal-continuous along the bridge, also the sliding layer and consolidation mechanism are set between the base plates and the bridge, so their inner interactive force is very complex when they subject to external force. In the past, it was rarely mentioned that which part of the rail system can affect the transfer of force when the system is subject to braking force. So on these premises, this paper focused on those aspects and had done a lot of work to seek for the solution. Firstly, it analyzed the loading characteristics of the CRTS II ballastless track slab on bridges;Then it built the corresponding calculation model;At last, the model was loaded according to the practical braking characteristics of the CRH trainThis paper also analyzed and calculated the distribution law of braking force produced respectively by different vehicle marshalling of CRH train, different fastening resistance,different friction coefficient of sliding layer and different consolidation mechanism stiffness.It finally came to the conclusion when the CRH train breaks, the rail and fasteners are loaded concentratedly, but the mechanical behavior of the substructures under rail is comparative smooth after the longitudinal-continuous rail slab and base plates transfer the braking force to other zones that are not loaded directly. When the number of units increases, the rail structure will correspondingly bear force of a larger magnitude;That the fastening resistance affected the rail's braking force greatly and had little impact on other components; The sliding layer friction coefficient interfere with the braking force of the bridge, because the sliding layer is the key mechanism to weaken the interaction of rail and bridge;The consolidation mechanism produced considerable influence on the transfer of braking force, it is the main element to transfer the braking force from the rail superstructure to the bridge piers. After careful comparative analysis, it is recommended that the value of the consolidation mechanism stiffness should be greater than 107 kN/m.