线路不平顺对桥上CRTSⅡ型板轨道振动的影响

Research on the Impact of Track Irregularities on the CRTS Ⅱ Slab Track Structure Vibration Characteristics

研究目的:轨道不平顺引起的列车振动和轮轨相互作用力随着列车速度的提高成倍增大。对车辆-轨道-桥梁耦合振动而言,桥梁变形和轨道不平顺相互叠加形成轨面位移,因而轨道不平顺对系统动力响应的影响更加显著。本文针对轨道不平顺对客运专线高架轨道结构振动特性的影响进行研究,分析三种实测中长波轨道不平顺状态,即路基有砟轨道不平顺、桥上有砟轨道不平顺以及隧道无砟轨道不平顺对高架轨道结构振动响应产生的影响。研究结论:(1)在相同运营条件、相同养护条件下,不同轨道结构的不平顺状态对轮轨冲击作用力、钢轨振动加速度、轨道板振动加速度的影响不同,但对桥梁振动加速度的影响较小;(2)在客运专线轨道中长波不平顺激励下,钢轨振动频率主要分布在20～250 Hz范围内,轨道板、桥面板垂向振动频率分布在20～150 Hz范围内,轨面不平顺度的波长成分是影响轨道结构振动频率分布特性的一个主要因素;轮轨力、钢轨振动加速度、轨道板振动加速度受随机不平顺的短波长成分的影响显著;(3)除了轨道结构类型的影响,轨道不平顺功率谱大小与波长特性对轮轨力、钢轨振动加速度、轨道板振动加速度也产生了显著的影响,建议在进行轨道不平顺控制时将轨道不平顺谱纳入高速铁路客运专线轨道质量的评价指标当中;(4)本研究成果对加深认识我国高速铁路轨道不平顺对高架轨道结构振动特性的影响具有一定的理论意义和实用价值。

Research purposes:Train vibration and wheel-rail interaction force caused by track irregularity increase exponentially with the increase of train speed.For coupled vibration of vehicle-track-bridge,the superposition of bridge deformation and track irregularity forms rail surface displacement,so the influence of track irregularity on system dynamic response is more significant.In this paper,aim to study the influence of track irregularity on elevated track structure vibration characteristics of passenger dedicated line,the dynamical responses induced by three-type long and middle wavelength irregularities were investigated in time-domain and frequent-domain.Three-type irregularities include the irregularities of ballast track on subgrade,the irregularities of ballast track on bridge and the irregularities of unballast track in tunnel.Research conclusions:(1)Under the same operation and maintenance conditions,the track irregularities of different track structures produce different impact on the wheel-rail interaction forces,steel rail vibration acceleration and track slab vibration acceleration,but produce little different impact on bridge vibration acceleration.(2)Under the long and middle wavelength irregularities stimulation,the vibration of steel rail mainly distribute in the range of 20~250 Hz and the vibration of track slab and bridge deck mainly distribute in the range of 20~150 Hz.The wavelength distribution of track irregularity is one of the main factors that influence vibration frequency of track.Wheel-rail force,rail vibration acceleration and track slab vibration acceleration are significantly affected by random uneven short-wavelength components.(3)Besides the type of track structure,the irregularities power spectrum and wavelength characteristics produce great impact on the wheel-rail interaction forces,steel rail vibration and track slab vibration.So it is suggested that the track irregularities spectrum should be contained in Chinese high-speed passenger dedicated-line track quality evaluation index system.(4)The research results will further improve the research level of high-speed railway track irregularities characteristics and the impact of it on track structure vibration characteristics.