The Study Of Unit CRTS â… Double-Block Ballastless Track

New Lanxin railway is located in northwest of China where climatic and environmental condition is harsh.Because of high temperature difference in a day or a year,CRTS I double-block ballastless track was choosed for this railway based on all kinds of conditions.As CRTS I double-block ballastless track is continuous structure,when the temperature changes heavily,there will be a serious problem that the structure is cracking and arching up.In order to solve this problem, the track slab was considered as the unit slab.The mechanical model was simply established mainly combined with CRTS I double-block ballastless track in the subgrade of new Lanxin railway which used unit slab.Then the mechanical model was divided elements with the finite element method,thus it was analysed to the force and deformation of the track structure.The analysis and research of the track structure were done from three respects:(1)Through the changes of the shear cam's height,it was analysed for the influence to the force and deformation of the track structure.(2)It was received for the mechanical properties of dowel bar and the best layout of it,by the analysis of the dowel bar in the expansion and contraction joint.(3) Applied temperature load to the track structure that with shear cam between the track slab and the supporting layer,and analysed the force and deformation of the track structure.The results show that, the higher shear cam can be choosed,but because of the thickness of the concrete cover,the height of the shear cam had to be restricted. The dowel bar can ensure horizontal and vertical stablity in the expansion and contraction joint effectively.When the temperature increases or decreases,the track structure will produce temperature deformation and contranction,and the coner of the shear cam will have greater stress concentration.So certain measures should be taken to reduce the stress concentration,such as using the shear cam with the fillet coner.The results of this thesis can provide the theoretical basis for the structure optimization of CRTS I double-block ballastless track and can provide the data reference for the experimental research.