The Analysis And Study Of A New Type Of Extensive Adjustment Unit Slab Track For High-speed Railway

With much more superior performance to slab track,slab track has been widely used in the construction of high-speed railway in China.Because of China’s vast territory,there are lots of complex terrain and climate conditions.As the continuous spread of high-speed railway network,there will be more slab track laid in the seasonal frozen soil regions,permafrost regions,complex and dangerous mountainous regions,weak soil layer and so on.The slab track in these regions has suffered a large number of foundation deformations caused by geology and climate,and there are many deficiencies in the current regulation methods.Therefore,this paper designed a new type of extensive adjustment unit slab track of high-speed railway and its specific height adjustment methods.Then,this paper analyzed the feasibility of the rail height adjustment scheme.Finally,the static and dynamic stress and deformation characteristics of the new slab track during operation are analyzed.The specific research contents are as follows:(1)Researched and summarized the existing rail height adjustment methods in China.Analyzed the advantages and disadvantages of the existing rail height adjustment methods.Designed a new type of large amount of adjustment unit slab track of high-speed railway and introduced the methods of raising and lowering the new track in detail.(2)Based on the beam-body static calculation model of slab track and the vehicle-track vertical coupling dynamics theory,the finite element software ANSYS and its dynamics module LS-DYNA were used to establish the finite element model for track static analyses during the jacking process,temporary support condition and operation period.Then dynamic analysis model of speed limit under temporary support condition and the dynamic analysis model during operation are established.Finally,relevant evaluation indexes are determined.(3)Analyzed the stress of each part of the track during the jacking process,discussed the rationality of the temporary support scheme,determined the vehicle speed limit value under the temporary support condition,and studied the feasibility of raising the new slab track.(4)Under the action of train load,overall temperature and thermal gradient,the influences of grinding thickness of rail bearing platform and track raising height on the stress and deformation of the track is analyzed,in order to ensure that there will be no over-limit stress and deformation during the normal operation and the operation after elevation adjustment.(5)The dynamic responses of vehicle and track under the condition of no elevation adjustment and the condition of raising and lowering are compared,and the influence of the elevation adjustment of track structure on the dynamic indexes of train passage is discussed.