Study On Structure And Mechanical Properties Of Gauntleted Slab Track On Steel Truss Bridge

This paper is based on the gauntleted slab track on the steel truss bridge located at the junction of Heilongjiang province and Russia.It is lack of theoretical research and engineering practice for track slab placed directly on the steel truss nor gauntleted track on the steel truss.In this paper,based on the theoretical analysis and laboratory test,the following conclusions are drawn for the gauntleted slab track on steel truss:(1)The finite element simulation model is established.After the stress calculation of the track structure,the bearing capacity and the reinforcement of the track slab are calibrated.Based on the modal analysis of the track structure,the first 30 modes of the system are obtained.Because of the short length and high constraint condition,the natural frequency of the track system is high.The natural frequency of the track system avoids the natural frequency of the bridge and the motivated frequency of the train load.(2)After the CWR calculation,it is found in the calculation of expansion and contraction forces that the amplitude of temperature variation has significant effect on the longitudinal force of steel rail.The temperature range of steel bridge is suggested to be researched for better result of CWR of track on steel bridge.Effect of connection resistance between track plate and beam on the calculation results is significant.It directly determines whether the result of CWR can meet the design requirements.Laboratory test is necessary to provide the accurate basis for analysis.The small rigidity of tie rod and diagonal tie connected longitudinally on the lower plane of steel truss bridge leads to large deflection of the beam and overgauge of the uplift force of the fastener near the crack under train load.Special fastener with large buckle pressure is necessary,otherwise the rigidity of tie rod and diagonal tie should be increased.(3)Several performances of the slab track on the steel truss bridge are tested through laboratory test,including crack resistance under static load,construction feasibility and fatigue performance.In the construction process,it is necessary to pay attention to the problem of leakage and the control of height of self-compacting concrete layer.The stress and displacement of the track structure are tested under the condition of static and dynamic load,and the results meet the requirements.The stress and deformation of the track structure are consistent with the simulation results,so it is feasible to analyze the stress and deformation of the structure in accordance with the above simulation.