| With the continuous progress of urbanization in China,the traffic congestion problem in China continues to heat up.As an advanced mode of transportation,the new tram can meet the needs of urban development with its advantages of convenience,speed,large traffic volume,high safety performance and low energy consumption.Embedded track structure is a kind of new tram track structure form,with continuous support and reduce the abnormal wear of wheel and rail and anti-vibration noise reduction,and the advantages of short construction period,based on embedded track huge application market and good damping noise reduction performance,this paper mainly on the embedded track longitudinal deformation and vibration characteristic is analyzed.The main research contents are as follows: a 600 mm double-layer poured embedded track full-scale model is designed and made to conduct longitudinal resistance and vertical stiffness parameter tests.Temperature load are derived based on the deformation characteristics of the embedded track on subgrade under embedded orbital mechanics equilibrium equation,seamless rail longitudinal displacement and longitudinal force calculation,analysis of changes in temperature,the longitudinal stiffness ratio,the embedded length of track circuit of rail longitudinal displacement and the influence of longitudinal force,discusses the application of the embedded track on railway roadbed is feasible,and compared with common rail longitudinal force and deformation analysis;Embedded track structure is the research object,the beam with single bridge is more than single span beam bridge embedded rail longitudinal force seamless parsing algorithm,to solve the calculation of rail longitudinal force,vertical displacement and the relative displacement of beam and rail,rail against temperature load,train load,brake load of the beam bridge under the action of embedded track interaction between beam and rail are analyzed;Analysis of beam body temperature difference,the longitudinal stiffness ratio and the pier stiffness on embedded rail expansion deformation force,the influence of the form analysis of beam section,rail type,load across a number of factors,such as for simply supported girder bridge embedded rail deflection force,seamless rail strength and relative displacement of beam and rail limits as control index,discusses the application of the embedded track on the feasibility of the simply supported girder bridge trams;Taking acceleration admittance as an index,the vertical vibration transfer characteristics and vibration reduction performance of embedded track components were studied by hammering test on the embedded track full-length model.The results show that:(1)Longitudinal resistance and vertical stiffness of the double-layer poured embedded track are subject to linear distribution.After linear fitting,the longitudinal resistance of the double-layer poured embedded track is 8.21 kn /mm / 600 mm,that is,13.08 n /mm2.The vertical stiffness is 49.1 kN/mm.When rail longitudinal displacement at 6 mm,filled polymer materials and support rail groove bonding surface bonding failure,continue to load up whole sliding rail and molecular materials,are unable to reset after unloading,safety coefficient is 1.2,ultimately determine the track plate displacement limit to 5 mm,rail longitudinal displacement limit value can be used as indicators of whether embedded track structure destruction.The results are in good agreement with each other through the finite element numerical simulation and the laboratory model test,which provides a certain method for testing the longitudinal resistance and vertical stiffness of the embedded track for reference.(2)The mechanical balance equation of the embedded track seamless line on the subgrade under the action of temperature load is derived to calculate the longitudinal displacement and longitudinal force of the rail.It can be concluded that the maximum values of longitudinal displacement and longitudinal force of the rail show linear changes with the increase of temperature.With the increase of the longitudinal stiffness ratio,the longitudinal displacement of the rail end decreases gradually.Laying length has little effect on the deformation of track structure.When temperature 50 ?,the strength of rail and rail longitudinal displacement can be met,so the embedded track applied to on railway roadbed is feasible.(3)Common end longitudinal displacement of track structure on subgrade is significantly higher than the embedded track,because of the embedded track on filled polymer continuous support to the rail,embedded rail longitudinal resistance can provide greater than normal track structure,rail longitudinal force of extreme value is the same,that rail longitudinal force and the longitudinal resistance,this relationship is determined by the temperature change amplitude,the stress of the telescopic area embedded track radiation rapidly.(4)An analytical algorithm for longitudinal force and longitudinal displacement of the embedded simply supported track girder bridge is proposed,which has the advantages of high calculation accuracy and efficiency,small cumulative error,standard solution and easy computer implementation.(5)As the temperature difference of the beam increases,the longitudinal displacement of the rail,the relative displacement of the beam and rail and the stretching force of the rail show a linear growth trend.When the temperature difference of the beam changes greatly,the longitudinal deformation of the embedded track is obvious,and the embedded track is not suitable for laying on the bridge with a large temperature difference of the beam.With the increase of the longitudinal stiffness ratio of the line,the relative displacement of the beam and the rail decreases gradually,and the telescopic force and the longitudinal displacement of the rail increase gradually.At the same time,it is found that the longitudinal stiffness ratio and the longitudinal stiffness of the pier have little influence on the longitudinal deformation of the embedded track.(6)Through the analysis of deflection deformation of box girder and t-girder,it can be seen that the form of beam section has obvious influence on the calculation of deflection deformation;The type of rail,the number of span imposed by load and the longitudinal resistance of the line have less influence on the deflection of the embedded track of the simply supported girder bridge than the section type of the simply supported girder bridge.(7)Working condition of braking force and bending force conditions,embedded track longitudinal deformation and stress are smaller,relative displacement of beam and rail does not exceed 1 mm far less than the limit value of embedded track damage,contractility condition than braking force and bending force conditions,when the beam embedded track railway Bridges expansion force condition as the main influence factors,and should focus on.(8)The acceleration of the embedded track rail admittance values are smaller,the response of the vibration picking point related to incentive point position,in the low frequency range of each measuring point response is reduced,in response to the increases with distance incentive point rail longitudinal vibration attenuation gradually,because of its inherent frequency peak appeared in the high frequency region,when the vertical vibration of rail to the support rail groove,the acceleration of a support rail slot admittance is far less than rail,that filled polymer materials has played a very good vibration damping effect.(9)There are multiple peaks in the vertical acceleration admittance 0-2000 hz of the common track structure.The resonance peaks of the common track structure are distributed in the full frequency band,and the rail vibration of the common track structure is relatively severe;Embedded track rail admittance acceleration peak value of acceleration is significantly lower,embedded in the 0-180 hz low frequency segment acceleration admittance rail are far less common track structure,the effect significantly,in 180-2000 hz segment acceleration peak value greatly decreases,and that the embedded track compared to the normal track structure has good anti-vibration performance,polymer filler material can significantly suppress the vibration response of the rail. |
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