高速铁路轨道运维拨道技术研究OA北大核心CSTPCDEI

To explore the optimization of reasonable operating parameters for high-speed railway rail shifting and track slab replacement,and further improve the efficiency of track slab replacement.Taking the renovation of existing operation lines for track shifting and slab replacement as the research object,combined with the actual track slab replacement operation testing on operation line,a finite element model of track shifting considering steel rails,fastener,and track structure was established.The effects of equipment layout spacing,fasteners release length,temperature difference,and other factors on track shifting operation under track shifting states were studied,providing data support and guidance for replacing damaged track slabs of different types and numbers.The studies show that before carrying out the lateral track shifting operation of the rail,it is necessary to primary analyze the relative spacing of each rail lifting device,track shifting device,and gauge tie rod,and determine a reasonable layout method of these devices.During the track shifting,the maximum pull-up force of the fastener is located at the position where the first set of fasteners has not been released.The pull-up force is influenced by the height of the tooling lifting rail and the length of the released fastener,and is not related to temperature.Under the limit value of 18 kN of buckle pressure,the minimum total length of the line under the transverse track of 750 mm rail reaches 80 m,which can ensure that the fastener does not experience upward movement.The maximum Mise stress of the steel rail is located on the inner side of the rail bottom at the gauge tie rod,decreasing from the point where the fastener is released to the center of the track.It is positively correlated with the degree of elastic deformation of the rail material.The maximum transverse tensile stress is always located at the lateral loading point of the track.The stress state is approximately inversely proportional to the length of the fastener release,which meets the requirements of the maximum allowable tensile stress limit of the steel rail.The temperature of the construction track is lower than the temperature of the locked track,which is the most unfavorable stress situation for the rail.To ensure that at least two track slabs can be replaced at once,it is recommended to have a minimum total length of 120 m for the track(with a fastener release length of 100 m).The present results can provide the reference for further optimizing the operation and maintenance technology of high-speed railway tracks and ensuring the safe operation of high-speed railways.