高速铁路无砟轨道结构基础变形分级评价

Classification Evaluation for Foundation Deformation of Ballastless Track Structure in High-Speed Railway

为阐明高速铁路线下基础变形对无砟轨道结构服役性能的影响规律,借以形成合理的基础变形评价体系,以CRTSⅢ型板式无砟轨道结构为研究对象,分别建立基础变形条件下无砟轨道结构静、动力学仿真分析模型,探究车辆-无砟轨道系统关键性能指标随基础变形幅值和波长的变化规律,并基于无砟轨道结构应力、离缝、不平顺及行车舒适性和安全性等指标提出基础沉降和上拱变形分级阈值。结果表明:当基础沉降/上拱波长小于15 m时,基础变形条件下无砟轨道结构应力容易超出强度限值,须将其作为关键控制指标;当基础沉降/上拱波长小于20 m时,基础变形对无砟轨道层间离缝的影响较为明显;当基础沉降波长在10~20 m范围时,轨道高低不平顺幅值较大,车辆-轨道系统动力响应达到峰值并影响行车舒适性。以无砟轨道结构服役性能、行车舒适性以及安全性为控制指标制定不同波长条件下基础变形分级评价体系,可为高速铁路无砟轨道结构的养护维修提供参考。

In order to clarify the influence laws of foundation deformation to the service performance of ballastless track structure under high-speed railway line for the purpose of forming a reasonable evaluation system for foundation deformation,taking the CRTSⅢslab ballastless track structure as the research object,the static and dynamic stimulation analysis models of ballastless track structure under the condition of foundation deformation were established individually.The variation laws of key performance indices of the vehicleballastless track system regarding different amplitudes and wavelengths of foundation deformation were studied;and the classified threshold values of foundation settlement and upper arch deformation were proposed based on indices involving structural stresses,disjoints,irregularities,driving comfort and safety of the ballastless track.The results show that the stress of ballastless track structure can easily exceed the strength limit under the condition of foundation deformation when the wavelengths of foundation settlement and upper arch deformation are less than 15 m,which need to be considered as a key control index.When the wavelengths of foundation settlement and upper arch deformation are less than 20 m,the influence of foundation deformation on the interlayer disjoints of ballastless track is obvious.When the wavelength of foundation settlement is within the range of 10-20 m,the amplitude of track longitudinal irregularity appears to be higher;and the dynamic responses of the vehicle-track system reach the peak and affect driving comfort.Taking the service performance,driving comfort and safety of ballastless track structure as control indices,the classification evaluation system for foundation deformation under various wavelengths is formulated,which can provide reference for the maintenance of high-speed railway ballastless track structure.