CA砂浆层破坏对无砟轨道结构受力特性影响OA

CA mortar layer falling is one of the most prominent diseases in the operation of ballastless track structure,and its damage degree has an important impact on the safety and applicability of ballastless track structure operation.The modified Burgers model is used to convert Prony series to characterize the viscoelasticity of CA mortar,and a three-dimensional finite element model of CRTS I-type slab ballastless track structure is established.By simulating the thin layer falling off of CA mortar layer at the end of the slab and in different areas of the slab,the effects of different falling off positions and sizes on the dynamic characteristics and structural displacement of ballastless track structure under wheel load are studied,and the evolution law and trend of track structure damage at the falling off point are analyzed,The recommended value of damage limit is given,which provides theoretical basis and guidance for the maintenance of ballastless track structure.The research results show that no matter the slab ends or the slab is broken,the CA mortar layer damage causes significant increases in the vertical acceleration,vertical displacement and longitudinal tensile stress of the track slab.The compressive stress at the edge of the CA mortar layer is sharply increased,while the vertical displacement and stress of the base plate are gradually reduced.Under the action of wheel load,when the thin layer of CA mortar plate ends drops to 0.912 5 m,and when the drop in the plate reaches 1.25 m,the vertical vibration of the track plate and the compressive stress of CA mortar will increase significantly.The track structure should be repaired in time to avoid rapid expansion of the track structure damage.