Slab Ballasted Turnouts Turnout District Board Mechanical Properties Analysis

Turnout is a kind of railway track equipment to make the rolling stock run from a track branch into another,or cross another track. At present, China railway is in a leap-forward development phase, the overall turnout technology of China railway moves from quasi high speed stage in to a new stge of rapid development. The safety and comfort of the scheduled passenger train running through the turnout propose higher demands for the smoothness and stability of the track. Ballastless turnout has the outstanding advantages of high stability, uniformity of rigidity, constancy of structure,easy maintain,etc, so it meets the requirements of high-speed railway. Today ballastless turnout has already been applied in high-speed railway and the passenger dedicated line in domestic country.Slab ballastless turnout is studied in this paper. As ballastless turnout differs from general section ballastless track structure, from the head of turnout to the end, the width of the track structure constantly changes, the number of the rail is large, and the interacts are complex, so support beam model can not be directly established. Therefore, considering ballastless turnout system as the beam-entity-entity composite structure system, a spatial finite element model is established by Ansys software, and a stress analysis of concrete slab in turnout area is conducted, mainly including:(1) Train dynamic model is established by ADAMS/Rail, and the dynamic response of the track structure is calculated by the constructed irregularity of turnout area structure when the train is running through the turnout;(2) Integrating thermal analysis with structural analysis, warpage analysis of the turnout slab is conducted, under the temperature gradient load, also analysis of the influence on warping stress and displacement of turnout slab caused by the change of elastic modulus of the base plate, thickness of the base plate, thickness and width of turnout slab is also conducted;(3) Under uneven settlement of foundation, the force and displacement of the turnout slab and the base plate is calculated, also conducted analysis focusing on the influence caused by settlement limits and thickness of the base plate, and then the rationality of simplified algorithm is evaluated comparing the results acquired from the finite element method and simplified algorithm.These results can be used to guide the design, construction and maintenance of slab ballastless turnout.