Study On Mechanical Characteristics Of New-style Transition Section Behind Abutment To The CRTS ⅡLongitudinal-Continuous-Slab Ballastless Track

With the high ride comfort, stability, durability and reliability, the ballastless track has been accepted by the high-speed railway all over the world. In our country, the track is also been used widely and through the introduction, digestion, absorption and re-innovation, a complete set technology of the CRTS II track has been formed. And the longitudinal-continuous-slab-type ballstless track on bridge is a new design idea which has great significance. The structure will bring about huge longitudinal temperature force and brake force and can transfer to the subgrade for that the ballstless track is continuous in the whole bridge. Consequently to resist it, the structure should set the terminal displacement configuration system (TDCS) which is different from the taditional transition section.In this paper, the study is mainly about two anchoring bolting systems which are been used widely: the inverted T-shaped TDCS and the double-column shaped TDCS. Through the comparison between them, the research can get the differences in which vertical index have been with the main concern and can select more reasonable anchoring bolting system.This paper has mainly done the following work:1) reading a large number of paper, have a detailed study to the anchoring bolting system of CRTS II longitudinal-continuous-slab-type ballstless track and collect the parameters of the inverted T-shaped TDCS and the double-column shaped TDCS. Based on the ABAQUS software the vehicle-bridge-subgrade model has been made in which the interaction relationship is considered2) The dynamic model can be used to study the matching relationship of rational rigidity between the track structure and subgrade, the influence to the anchoring bolting system with the different train speed and direction, the influence of vertical stiffness with different roadbed filling in the scope of anchoring bolting system, the influence of uneven settlement in the transition section to comfort and to the interaction between the vehicle and line. Research shows that:the main TDCS has a big stiffness, vertical acceleration and a small vertical displacement. The largest vertical displacement occurred behind the TDCS where it is a wesk point. Driving speed has a great influence to the rate of wheel load reduction.To verify the rationality of the model, the results have been compared with the test results.3) Based on the research results in front, the research compared the new-style tansition section with the taditional transition section, and compared the inverted T-shaped TDCS with the double-column shaped TDCS at the same time. Research shows that:compared with the taditional transition section, the new-style transition section reduced the vertical displacement and the rate of wheel load reduction and changed little to the the lateral and vertical wheel-rail force and acceleration of vehicle. Compared between the new-style transition section, the vertical wheel-rail force has little difference between them in the same velocity, but the lateral and vertical acceleration in the inverted T-shaped TDCS is lager than the double-column shaped TDCS; The integral rigidity of the T-shaped TDCS is lager than the double-column shaped TDCS; Compared with the double-column shaped TDCS, the inverted T-shaped TDCS has a smaller vibration in the action of dynamic loading.And Make a optimization according to their characteristics.The results show that the indexs has greatly improved after optimization.