Study On The Optimization Of The Intercity Slab Ballastless Trace Structure

As a new express railway from Chengdu to Dujiangyan after Wenchuan Earthquake, with the design speed 200 kilometers per hour, the latest designed ballastless track structures which have independent intellectual property rights are adopted in some of track structures of Cheng-Guanxian inter-city railway. This ballastless track structure is element slab ballastless track on bridges, using self-compacting concrete instead of CA mortar as the fill layer under the plate. Meanwhile, in order to strengthen the connection between the slab and self-compacting concrete, U-section steel bar is set between them. Two convex plates are set on the base plate to transfer lateral and longitudinal force, and movements of the slab are limited. The ballastless tracks on the sub-grade connect longitudinally. The interspaces between slabs are filled with colophony mortar and the places under the slab are full of self-compacting concrete. Then the HGT is used as the supporting layer. Since it is the first time for the ballastless tracks used in our country, there is very important significance to research this structure.This thesis mainly introduces the studying, designing and the structural features of Chengdu-Guanxian railway ballastless track, and the problems at the present are summarized. For the target speed 200km/h, it is complex for longitudinal connected slab ballastless track on the subgrade to construct and inconvenient to maintain, at the same time, it costs a lot. Aimed at these defects, this thesis puts forward element slab ballastless track, which cancels the longitudinal connected slab and the resin mortar between slabs, but fills up self-compacting concrete under the slab, and sets up the limiting grooves on the base plate. By the model calculation, it is tested and verified that the element slab ballastless track can meet the requirements under the effect of train load and temperature load. Through the comparison analysis, element slab ballastless track can endure the effect of temperature load very well. However, under the effect of train load there will be concentrated force at the notch, so it is necessary to set up flexible cushion there. As for longitudinal connected slab ballastless track, there is less effect under the function of train load because of its integrity, but it has little ability to endure temperature load. With regard to element slab ballastless track, this thesis analyzes the influence of the ways of limiting grooves, the thickness of self-compacting concrete and base plate in detail, in addition, suggestions due to analysis results are proposed.Ultimately, the analysis and study toward the slab ballastless track on the subgrade achieve the purpose of optimizing the ballastless tracks.