客运专线无砟轨道无缝线路锁定轨温确定方法的探讨

根据客运专线无砟轨道无缝线路的结构和受力特点,采用现场试验、调研和动力仿真等方法对既有无砟轨道无缝线路锁定轨温的影响因素进行系统分析。研究结果表明:锁定轨温降低后,无缝线路温升幅度增大,温降幅度减小,将导致无缝线路施工和维护困难、钢轨发生碎弯几率增大等问题,影响高速列车运行的平稳性和安全性;在确定客运专线无砟轨道无缝线路锁定轨温时,除了要对无缝线路的强度、稳定性等进行常规检算外,还应结合车辆-轨道耦合动力学理论进行升温条件下钢轨碎弯变形的检算,从而确定合理的锁定轨温范围。为此建议对无砟轨道无缝线路碎弯变形的产生机理、不利影响及钢轨的合理断缝允许值进行静、动力学理论分析和试验研究。

Study on the Determination Method for Stress-Free Temperature of CWR in Ballastless Track of Passenger Dedicated Line

According to the structure and the mechanical characteristics of CWR(continuously welded rail) in ballastless track for passenger dedicated line,systemic analysis on the influencing factors of stress-free temperature is carried out using field test,investigation and dynamical simulation.The research results show that when the stress-free temperature drops,the scope of CWR temperature rising would be magnified.The decrease of temperature dropping scope will result in such problems as the difficulties in CWR construction and maintenance,the probability increase of the occurrence of rail continuous bending deformation, etc.These problems will affect the riding quality and the operation safety of high-speed trains.For determining the stress-free temperature in ballastless track for passenger dedicated line,the strength,stability and other indices of CWR should be checked and calculated.In addition,combined with vehicle-track coupling dynamics,the continuous bending deformation of rail temperature rising should be checked and the reasonable stress-free temperature can be confirmed subsequently.Therefore,it is suggested that the generation mechanism and unfavorable influence of continuous bending deformation,and reasonable allowable width of CWR breaking joint in ballastless track should be studied through static and dynamic theoretical analysis and tests.