Good interlayer interface performance is the key to maintaining the stability of CRTSⅡslab ballastless track structure.In a project,the tangential cohesion parameters of CRTSⅡslab ballastless track structure are gen...Good interlayer interface performance is the key to maintaining the stability of CRTSⅡslab ballastless track structure.In a project,the tangential cohesion parameters of CRTSⅡslab ballastless track structure are generally measured by horizontal push plate test,so as to measure the interlayer interface performance.Horizontal push plate contraction scale and full scale tests of CRTSⅡslab ballastless track structure are carried out to obtain the tangential force-displacement relation curve of the interlayer interface,thus obtaining the parameters of cohesion model.A threedimensional progressive damage analysis model for CRTSⅡslab ballastless track structure is established,the whole process inversion of the horizontal push plate test is carried out,and the reliability of the contraction scale test results is verified by means of simulation and comparative analysis of test results.The results show that the greater the tangential stiffness of the interlayer interface of the track structure,the weaker the interlayer deformation coordination capability;the more significant the non-uniformity of the interface damage,the more likely the stress concentration;the greater the fracture toughness,the less likely the disjoint in the interlayer interface of the track structure.展开更多
A ballastless slab track,which is commonly used in the track structures of heavy-haul railway tunnels,was analysed based on field measurement data of the Fuyingzi Tunnel on the Zhangtang Railway.In accordance with the...A ballastless slab track,which is commonly used in the track structures of heavy-haul railway tunnels,was analysed based on field measurement data of the Fuyingzi Tunnel on the Zhangtang Railway.In accordance with the measured data,the dynamic load thresholds and distributions on the surface and bottom of the ballastless slab track were investigated.A fatigue damage analysis of the ballastless slab track was performed based on the dynamic load time–history curve.The results show that the ballastless slab track can accomplish train load attenuation and reduce the dynamic load from heavy-haul trains by 47.22%from the surface to the bottom.In addition,the distribution at the bottom of the ballastless slab track exhibited a triangular shape,and the dynamic load threshold at the line centre accounted for 78.67%of that at the track position.Meanwhile,the distribution at the surface was saddle-shaped;the dynamic load threshold at the track position accounted for 79.55%of that at the line centre position.The fatigue damage of the ballastless slab track was analysed effectively by combining the measured data and the linear fatigue damage theory.Moreover,the accuracy of the calculation results was verified based on the measured dynamic stress of the ballastless slab track structure.The dynamic action of the train load led to more-concentrated damage to the track bed,and the damage occurred earlier than that in the ordinary line.The axle load was the primary influencing factor of the track bed fatigue damage,and the damage mainly occurred in the track position.These results provide a theoretical basis for performing stress analysis and designing parameters for ballastless slab tracks in heavy-haul railway tunnels.展开更多
文摘Good interlayer interface performance is the key to maintaining the stability of CRTSⅡslab ballastless track structure.In a project,the tangential cohesion parameters of CRTSⅡslab ballastless track structure are generally measured by horizontal push plate test,so as to measure the interlayer interface performance.Horizontal push plate contraction scale and full scale tests of CRTSⅡslab ballastless track structure are carried out to obtain the tangential force-displacement relation curve of the interlayer interface,thus obtaining the parameters of cohesion model.A threedimensional progressive damage analysis model for CRTSⅡslab ballastless track structure is established,the whole process inversion of the horizontal push plate test is carried out,and the reliability of the contraction scale test results is verified by means of simulation and comparative analysis of test results.The results show that the greater the tangential stiffness of the interlayer interface of the track structure,the weaker the interlayer deformation coordination capability;the more significant the non-uniformity of the interface damage,the more likely the stress concentration;the greater the fracture toughness,the less likely the disjoint in the interlayer interface of the track structure.
基金the Open-end Fund of Key Laboratory of New Technology for Construction of Cities in Mountain Area(LNTCCMA-20210108)the National Natural Science Foundation of China(5108098)+5 种基金the Chongqing Education Commission Science and Technology Research Project(KJQN201901509)the Chongqing Natural Science Fund General Project(cstc2020jcyj-msxmX0904)the Chongqing Talents:Exceptional Young Talents Project(cstc2021ycjhbgzxm0246)the China Postdoctoral Science Foundation-General Project(2021M693739)Chongqing Talents:Exceptional Young Talents Project(cstc2021ycjhbgzxm0246)China Postdoctoral Science Foundation-General Project(2021M693739).
文摘A ballastless slab track,which is commonly used in the track structures of heavy-haul railway tunnels,was analysed based on field measurement data of the Fuyingzi Tunnel on the Zhangtang Railway.In accordance with the measured data,the dynamic load thresholds and distributions on the surface and bottom of the ballastless slab track were investigated.A fatigue damage analysis of the ballastless slab track was performed based on the dynamic load time–history curve.The results show that the ballastless slab track can accomplish train load attenuation and reduce the dynamic load from heavy-haul trains by 47.22%from the surface to the bottom.In addition,the distribution at the bottom of the ballastless slab track exhibited a triangular shape,and the dynamic load threshold at the line centre accounted for 78.67%of that at the track position.Meanwhile,the distribution at the surface was saddle-shaped;the dynamic load threshold at the track position accounted for 79.55%of that at the line centre position.The fatigue damage of the ballastless slab track was analysed effectively by combining the measured data and the linear fatigue damage theory.Moreover,the accuracy of the calculation results was verified based on the measured dynamic stress of the ballastless slab track structure.The dynamic action of the train load led to more-concentrated damage to the track bed,and the damage occurred earlier than that in the ordinary line.The axle load was the primary influencing factor of the track bed fatigue damage,and the damage mainly occurred in the track position.These results provide a theoretical basis for performing stress analysis and designing parameters for ballastless slab tracks in heavy-haul railway tunnels.
