The Mechanical Analysis Of Slab Track On Soil Formation

With the rapid development of modern high-speed railway and city masstransit, slab track of which character is less maintenance or no maintenance was developed rapidly. In the phase of calculation for slab track structure before, model simplify has been done for different degree, but the importance of bedding to the slab track, and this can not reflect the real stress state of slab track more completely. This thesis focuses on the slab track layed on the soil formation. A mechanical model of slab track layed on the soil formation is established, and system analysis is made for its stress performance.The model is built using the solid element, and every part of the model is simulated with real size. Because the slab track is layed on the soil formation which has smaller stiffness, we have more advanced requirement to the bedding, this thesis considers the bedding, and simulate the bedding by D-P material. Considering the material difference of concrete basement and bedding, contact element is adopted to analyse the connection.Toword the condition of laying slab track on the soil formation, in order to analyse whether the deformation and stress go beyond the allowable range of slab track, five work condition was selected to load. The analysis result indicate that only with the load that considering some dynamic coefficient, the vertical settlement and stress of slab track structure in vertical direction is very low, and will not exceed the adjust amount slab track itself. Basement and bedding is not contact quietly, and the phenomenon of edge warp occur in the concrete basement, and the bedding is not tensed in vertical direction, which meet the material characteristics of bedding. And bigger inflected area of the slab appears in both vertical and longitudinal direction, so we can know both upper and lower surface of slab has the probability to be tensed or compressed, and the longitudinal stress is bigger than lateral and vertical stress, and the slab should have the double-deck and two-way reinforcement.Different Young's modulus and Poisson's ratio are selected to calculate the bedding, the analysis results indicate that the deformation of slab track can bereduced with increasing the Young's modulus meanwhile decreasing the Poisson's ratio of the structure; concrete basement has the most apparent influence under the change of bedding condition, and which can decrease the longitudinal stress of the slab in wide-range, and decrease the reinforcement.The analysis results of this model, can be used in the design of slab, concrete basement and bedding of slab track.