Research On The Adaptability And Static Irregularity Evaluation Of Ballastless Track Of Long Span Cable-stayed Bridge In High Speed Railway

Laying ballastless track on long span cable-stayed bridge can unify the whole track type and eliminate the line speed limit point,which is the inevitable trend of the development of high-speed railway.However,the coordination mechanism of stress and deformation of ballastless track of long span cable-stayed bridge under train and temperature load is not clear,and there is a lack of reasonable evaluation method of static irregularity of ballastless track of long-span bridge.In this thesis,Ganjiang Bridge,Dongping Bridge,Jiaojiang Bridge and Hutong Bridge with main spans of 300 m,350 m,480 m and 1092 m are taken as the research objects.The ballastless track interaction,vehicle-bridge dynamic response and track static irregularity evaluation of long span cable-stayed bridge under train and temperature are studied.The main work is as follows :(1)Coordination analysis of static force and deformation of ballastless track on cable-stayed bridgeFor the ballastless track structure system of long-span cable-stayed bridges,establish a static nonlinear calculation model,clarify the load parameters and working conditions,and form a general calculation method;explore the adaptability of ballastless track systems of different spans of cable-stayed bridges under the action of trains and temperatures properties,study the influence of fastener types(constant resistance,small resistance)on the longitudinal slip of the fastener,the influence of the commonly used isolation layer types on the deformation coordination between the track layers,and provide suggestions for the selection of ballastless track fasteners and isolation layers.(2)Research on the running performance of long span cable-stayed bridge ballastless track considering additional temperature deformationThe train-track-bridge dynamic analysis model is established,the track deformation under the most unfavorable temperature conditions is extracted,and the most unfavorable track surface deformation under the action of temperature is superimposed as a sample of additional track irregularities and random track irregularities,and the train-ballastless track-The adaptability analysis of long-span cable-stayed bridges is carried out,and the influence of the temperature deformation of the track surface on the dynamic response of the bridge is studied.(3)Research on static irregularity evaluation of ballastless track of long span cable-stayed bridgeThe current standard 300 m chord index is not suitable for the evaluation of the track irregularity on the bridge when the lower bridge has large deformation.In view of this deficiency,two long-wave irregularity evaluation methods on long-span bridges are proposed: Method 1: 300 m chord index and vertical curve radius Joint evaluation method: The relative deformation of the track and the construction error are evaluated by the300 m chord index,and the fitted bridge deformation is evaluated by the vertical curve radius.Method 2: Establish the relationship between the vertical acceleration of the car body and the chord vector distance.From the perspective of controlling the vertical acceleration of the car body,an evaluation index of 40 m chord length and 5mm vector distance is proposed.Both methods achieve a reasonable evaluation of the long-wave irregularity of the track on the cable-stayed bridge in the background project of this thesis.