纵连式无砟轨道端刺区结构服役稳定特征分析

Analysis on Stability Characteristics of Structure in Back End Zone of Longitudinally Connected Ballastless Track in Service

路桥过渡段范围的结构受力特征较为复杂,是轨道结构的薄弱环节。随着运营时间的增长,部分线路端刺锚固结构不可避免地出现较大水平位移,影响上部轨道结构稳定性。针对运营期纵连式无砟轨道端刺区结构稳定特征开展了现场调研和监测,结果表明:锚固结构变形特征表现为过渡板与路基支承层之间的水平位移,且呈现出随季节性温度而周期性变化的规律;受端刺锚固结构水平位移的影响,路桥过渡段结构伤损区域分布特征明显,集中在过渡板末端靠近路基范围,主要表现为轨道结构关键连接部位离缝、轨道板端上拱、宽窄接缝挤压破碎等。建议针对运营期台后锚固限位结构服役状态进行系统性监测,并进一步跟踪分析结构伤损发展规律,为科学合理地制定专项养护维修技术提供支撑。

The structural stress characteristics within the bridge-subgrade transition section are comparatively complicated,which is the weak points of track structure.With the increase of transportation service time,larger horizontal displacement of anchor structure inevitably occurs in railways,and influence the stability of track structure.On-site special investigation and monitoring were carried out according to the stability characteristics of the anchor structure at the back end of the longitudinal connected ballastless track during operation.The results show that the deformation characteristic of the anchor structure is manifested as the horizontal displacement between the transition plate and the subgrade supporting layer,revealing the regularity of periodic change with seasonal temperature.Considering the influence of horizontal displacement of the end stab,the distribution characteristics of structural damage area in bridge transition section were obvious.And these characteristics were concentrated at the end of the transition plate near the roadbed,which was mainly manifested as the disconnection of key connection parts of the track structure,the upwarp at the end of the track plate,and the crash of wide and narrow joints.It was suggested to systematically monitor the service state of anchor structure behind the abutment during the operation period,and further follow-up and analyze the development law of structural damage,which could provide support for scientific and reasonable formulation of special maintenance technical measures.