Structural Parameter Optimization Of Sleeper Slab Ballastless Track On Open Deck Of Long-span Steel Truss Flexible Arch Bridge

The steel truss flexible arch bridge has the advantages of large carrying capacity and strong spanning capacity.It has good adaptability to the large-span open deck passenger and freight railroad.The laying of slab ballastless track on the open deck of the large-span steel truss flexible arch bridge can not only Increasing the integrity of the track structure facilitates the vertical and horizontal positioning of the track structure,and can also reduce the dead load of the second phase of the bridge and improve the economy of the bridge.At present,the open deck ballastless track for steel truss bridges is mainly concentrated on small and medium-span steel bridges or special steel bridges for urban rail transit.For large-span steel truss flexible arch bridges,the open deck passenger and freight railroad slab track structure is rare.There are studies,therefore,it is clear that the static and dynamic performance of the slab ballastless track on the open deck of a large-span steel truss flexible arch bridge is of great significance to the safety of line operation.This paper takes the under-construction bridge across the Hongqili River Road as the research background,takes the sleeper slab ballastless track on the bridge as the research object,and uses ANSYS/LS-DYNA to co-simulate it,and the open deck of the long-span steel truss flexible arch bridge The static and dynamic performance of sleeper slab ballastless track is studied.The main research contents are as follows:(1)According to the literature research on domestic and foreign large-span steel truss flexible arch bridges,open deck track structure and vehicle-line-bridge coupling research status,it is clear that the slab ballastless track should be laid on the open deck of the long-span steel truss flexible arch bridge.Existing research is insufficient.(2)Use ANSYS finite element software to establish a static model including polymer concrete cushion,sleeper slab,rail support,limit tube,filling layer and high-strength bolts,and determine the size of sleeper slab,fastener stiffness and slab The reasonable range of the seam layout was determined,and the filling layer material was optimized.(3)Considering the track irregularity caused by the temperature load of the super bridge across Hongqili Waterway,superimposing it with the spectrum of my country’s three major trunk lines to form a new track irregularity,using LS-DYNA to establish the vehicle-linebridge coupling dynamics model of the bridge,Calculated its natural vibration characteristics,and compared the dynamic response of the car body,track structure and bridge with sleeper slab ballastless track and composite sleeper track on the exposed deck of a large-span steel truss flexible arch bridge.(4)The thickness,length and fastener stiffness of the sleeper plate of the sleeper slab ballastless track are optimized for dynamic parameters,and their influence on the dynamic response of the system is analyzed.A dimensionless method is used to propose a reasonable range of related parameters.