Analysis Of The Multi-layer Structures On The Subgrade Of The High-speed Railway

With the increasing speed of the train, the force between wheels and the railbuilds up. Hence, under the impact of train running load, the track structure is proneto be damaged without reasonable setting of parameters, which would pose a threat todriving comfort and safety. Plus, lifetime of the track structure would be greatlyreduced. There are many factors that could make influence to the dynamiccharacteristics of the vehicle-track-subgrade system, such as speed and axle load ofthe train, stiffness and damping of the fasteners, thickness and rigidity of the rail plate,and size and stiffness of each subgrade layer’s structures (the subgrade’s supportingstiffness changes under different geological conditions). However, these factorswould also make different impacts on the V-T-R system. In order to optimize thedynamic performance of the ballastless track system on the subgrade, and to provideguiding suggestions to dynamic monitoring of the multi-layer structures on thesubgrade, it is of great necessity to make researches and analysis on how greatlyparameters of the structure has influenced the structure itself.This article develops on the basis of the following main contents.First, establishing slab track coupling statics analytic model; making analysis onhow changes of parameters of fasteners’ stiffness, elastic modulus of CAmortar layer,and stiffness of foundation under the Z-K live load have effects on staticscharacteristic of multi-layer structures; making sure of the extent and rule of impactof different parameters on multi-layer structures.Second, making research on the natural vibration characteristics of theballastless track on the subgrade; determining the model size of its modal analysis;making analysis of the impact of parameters of the ballastless track’s multi-layerstructures on the structures’ natural vibration characteristics; determining the extentand rule of the ballastless track’s natural frequency of vibration on the subgrade;making suggestions on the dynamic monitoring of the ballastless track’s structure.Third, making analysis of the dynamic characteristics of the ballastless track on the subgrade under moving loads; researching the extent and rule of impact ofparameters on the ballastless track under moving loads by altering parameters ofmulti-layer structures; verifying the extent of impact of different parameters onstructures; offering advisory opinions on how to optimize the design of the ballastlesstrack’s structures.