Study On A Ballastless Tracks Structure That Can Adapt To The Settlement Of Track Foundation

The settlement and upper arch of ballastless track roadbed,bridge and tunnel are particularly serious.For some of the settlement and upper arch sections of ballastless track,such as foundation roadbed,bridge roadbed and tunnel roadbed are particularly serious.Subgrade settlement has been beyond the adjusting range of railway fasteners,unable to meet the basic requirements of the standard high orbit,the current domestic generally adopt methods to control or mechanical lifting and grouting,but due to the quantity of construction project cycle is long,big,high cost,cost a lot of manpower material resources,in the process of grouting can’t accurate and efficient rail board level adjustment.On the basis of the existing treatment methods,this dissertation proposes a kind of highly adjustable ballastless track structure,aiming at using this new track structure to change the subgrade settlement and upper arch problems over 20 mm to 200 mm from subgrade regulation to track regulation.(1)In order to determine whether the mechanical properties of the height adjustable ballastless track structure meet the requirements of use,this dissertation takes elasticity as the theoretical basis,and carries out static analysis and dynamic analysis on the new track structure in the finite element calculation software.The three-dimensional finite element model of highly adjustable ballastless track structure was established.The mechanical properties of rubber materials were compared under different side cushion thicknesses,different die drawing degrees and different overall curves.The modal modes of this track structure in the overall assembly body were analyzed,and the stability of its sleeper at a height of 200 mm was tested.Research results show that the elastic lateral plate for a greater influence on the structural vibration mode,and the overall taper less influence on the structural modal vibration mode,for the curvature of the overall structure of the modal of a greater influence on the vibration mode and natural frequency,the structure can be up to 200 mm in sleeper keep after the first order modal vibration mode is vertical downward,namely the structure to remain stable under alternating load train.(2)Based on the vehicle-track coupling dynamics theory,the driving safety and ride stability of the elastic side pad under different working conditions are calculated and analyzed,as well as its practicability.The results show that after the sleeper raise,sleeper acceleration and displacement increased,in order to ensure the structure during the train operation safety and stability,change the structure stiffness make sleeper raised after the acceleration response and displacement response of the consistent before and did not raise,the results show that this structure can effectively restrain from the vibration of the train,and consistent with the sleeper has not raised before.The height adjustable ballastless track structure proposed in this dissertation can not only maintain the stability of the structure itself under the change of the elastic side cushion thickness,the overall taper,the overall curvature and sleeper height and other important parameters,but also the vehicle stability,safety and comfort and other vehicle basic evaluation indexes are within the required range.