Dynamic Response Analysis Of CRTS Ⅰ Slab Track On Subgrade Under Earthquake

Slab ballastless track, for its good performance at smoothness stability and durability, has been widely used in high-speed railway construction at home and abroad. However, rsearches at home and abroad show that both ballasted and ballastless track are subjected to varying degrees of damages under powerful earthquake. Compared with ballasted track, maintenance of ballastless track is more difficult once destroyed. Therefore,it is necessary to analysis anti-seismic performance of ballastless track structure.Firstly, this paper briefly introduced earthquakes and seismic waves, as well as development of anti-seismic engineering. Meanwhile, the paper summarized structure types and characteristics of slab track as well as its anti-seismic research status at home and abroad. Then a 3D finite element model, which take intact condition of structure and damaged filling resin into account, respectively, of CRTS I slab track on subgrade was built with ANSYS.Dynamic response of ballastless track on subgrade under different earthquake magnitude and hypocentral location was calculated by dynamic anti-seismic time-history analysis method.The research result shows that:the dynamic response of each part of the structure is consistent with the trend of the seismic wave acceleration; the location of the seismic source makes the significantin fluence on the rail structure, when the seismic waves propagate along longitudinal direction, its impact on track structure is much larger compared with seismic waves propagate along longitudinal.The damage of the filling resin has a greater impact on the unit track slab than the base slab.In the case of filling resin damaged, the seismic dynamic response of the track slab increases by 50%, the dynamic response of the base slab increases 10%-20%. However, the damage of the mortar leads to a small amplitude reduction of the dynamic stress during earthquake.Briefly, for ballastless track under earthquake of magnitude 8 or less, when track structure is intact or the filling resin is damaged, the longitudinal and lateral displacements are small in earthquake. The dynamic tensile and compress stress of concrete is much less than the ultimate strength of concrete, so it will not cause the structural damage of ballstless track.