| CRTS Ⅱ slab ballastless track relies on the bond between the track slab and the mortar layer and the connection between the width and narrow joints of the track slab to maintain the longitudinal stability of the track slab.In the high temperature season,the track slab will arch up,so the CRTS Ⅱ slab ballastless track is unitized.The vertical stability of CRTS Ⅱ slab ballastless track under different unitization schemes is not clear after heating up again.Under the effect of foundation deformation,the influence of the length of units and the elastic modulus of the filling material between units on the vertical stability of track structure also needs to be further studied.Based on the summary of the research status of CRTS Ⅱ slab ballastless track at home and abroad,the paper makes the unit of CRTS Ⅱ slab ballastless track.On this basis,the three-dimensional finite element models of simply supported beam bridge unitized CRTS Ⅱ slab ballastless track and subgrade unitized CRTS Ⅱ slab ballastless track are established,considering the influence of unitized length and filling material on the vertical stability of unitized CRTS Ⅱ slab ballastless track under the condition of overall temperature rise when bridge creep and uneven settlement of subgrade occur.The influence of the deformation of CRTS Ⅱ slab ballastless track on its vertical stability is analyzed when the length of element and the filling material between elements are different under different foundation deformation.The failure form of CRTS Ⅱ slab ballastless track after uniting is discussed preliminarily.On the basis of considering the longitudinal additional stress and failure form of track slab,the optimal unit scheme of CRTS Ⅱ slab ballastless track is put forward.The results show that after the unitized,the deformation of the substructure of the track structure will lead to the interlayer void or joint separation of the track structure,and the following deformation will occur in the CRTS Ⅱ slab ballastless track after the unitized,which will affect the vertical stability of the track structure.The vertical stability of CRTS Ⅱ slab ballastless track in different sections is most affected by the length of the unit and the filling material between the units.When the elastic modulus of the filling material between the units is very small,the CRTS Ⅱ slab ballastless track in the bridge section has the risk of vertical instability;while the CRTS Ⅱ slab ballastless track in the subgrade section has the risk of vertical instability only when the length of the unit is two slabs.When the elastic modulus of the filling material between the elements is greater than 100 MPa,the CRTS Ⅱ slab ballastless track in different sections will not lose stability,and its failure mode is compression failure. |
