Study On Spatial Mechanical Characteristics Of Ballast Jointless Turnout On Bridge

Continuously Welded Rail (CWR) track across section is a new type rail track structure, the rail joints are removed, and the rail track is completely jointless, and it has many merits. Because CWR track across section is suit for the development of high speed and over loading railway, CWR track across section developed quickly throughout the world.Jointless turnout is a key technique in developing CWR track across section. The structure of jointless turnout is complex, and calculation of longitudinal forces and displacements of tracks in turnout area are the basis of design, construction and maintenance of jointless turnout. With the development of high speed railway and urban rail transit, turnouts are laid on bridge, longitudinal force and displacement in tracks of turnouts become much complex. Researches of turnout on bridge are imperative..It is obvious that turnout laying on bridge is a technical subject on the development of CWR. It can't be solved with the theory of CWR on bridge or jointless turnout separately. Consequently, Some improvements are done to the finite element method, the longitudinal-lateral-vertical coupling modal of jointless turnout on bridge is established. The forces and displacement of jointless turnout are computed. Through contrasting with the result of jointless turnout on slab track and on bridge .The most factors which affect jointless turnout on ballastless bridge are analyzed: such as amplitude of temperature variation, resistance of blast, resistance of fastener, retainer, clamping, bridge structure, turnout welding structure etc. In this paper, summary analysis has been done on the position of the most unfavorable load. The condition of additional expansion force and additional flexural force on ballasted track is compared with that on ballastless track. The results can be used to guide the design and the maintenance of jointless turnout on ballastless bridge.