Research On The Warping Deformation Of The Embedded Track Slab In Hardening Areas

With the rapid development of urban rail transit in China, embedded track structure is introduced into the domestic by the first time, and there is a big difference in the structural pattern between embedded track structure and ballastless track structure of passenger dedicated line,and the problems of temperature warping of track slab are not yet clear. The warping deformation of the embedded track slab in hardening areas is researched which is under the temperature gradient load on the basis of the research findings about the warping deformation of track slab structure at home and abroad, and the warping deformation law of track slab under different constraints is found.At the same time, the effect of the self-compacting concrete elastic modulus, the track slab’s thickness and the track slab’s length on the warping deformation is analyzed to provide reference for design and optimization of the embedded track structure in hardening areas. The main work and conclusions of this research include the following aspects:(1)The warping deformation of track slab under different constraints and load combinations was analyzedThe warping deformation of track slab under different constraints and load combination was calculated according to the finite element entity model of the embedded track structure in hardening areas, and the results show that the greater the constraints on track slab is, the smaller the warping and displacement are, while the greater warping stress is, the stress and displacement of track slab only fluctuate within the scope of load constraint it subjected to.The difference between the maximum warping stress calculated by the analytical method and the finite element numerical calculation results reaches 5.5～12.2%,and the difference between the maximum warping displacement and the finite element numerical calculation results reaches only 3.0%,which proves that it is appropriate to use analytical calculation method to calculate the warping deformation of the embedded track slab in hardening areas because it can not only guarantee veracity but also verify the accuracy and reliability of the finite element model.(2)The effect of self-compacting concrete elastic modulus on the warping deformation of track slab was researchedThe effect of self-compacting concrete elastic modulus on the warping deformation of track slab was researched according to the finite element entity model, and the results show that with the increase of the self-compacting concrete elastic modulus, the warping displacement of track slab decrease, while the warping stress increases, so it is necessary to further reduce the elastic modulus and improve the anti wheel rail impact ability when meet the self-compacting concrete own characteristics.(3)The effect of the track slab’s thickness on the warping deformation of track slab was researchedThe effect of the track slab’s thickness on the warping deformation of track slab was researched according to the finite element entity model, and the results show that with the increase of the track slab’s thickness, the warping displacement of track slab increase, while the lateral warping stress decreases, and the longitudinal warping stress increases firstly and then decreases. On the basis of the stress and deformation condition of track slab, the track slab’s thickness is recommended for 0.36 meters.(4)The effect of the track slab’s length on the warping deformation of track slab was researchedThe effect of the track slab’s length on the warping deformation of track slab was researched according to the finite element entity model, and the results show that with the increase of the track slab’s length, the warping displacement of slab changes very little, the longitudinal warping stress increases,while the lateral warping stress is hardly affected by the slab’s length change. On the basis of the stress and deformation condition of track slab, as well as the situation of economic benefits and other factors, the track slab’s length is recommended for 5.40 meters.