连续梁桥典型变形对轨道几何形位演变的影响

研究目的:连续梁桥变形引起的轨道几何形位演变直接影响线路运营速度和行车安全。轨道几何形位演变的有效防控是保证轨道平顺性的核心关键。以考虑两侧简支梁引桥及路基影响的3跨连续梁桥为研究对象,基于作者已建立的连续梁桥典型变形引起轨道几何形位改变的映射解析计算模型,定量化研究桥墩沉降,梁端横、竖向转角及梁体横、竖向错台等典型变形对CRTSⅡ型板式无砟轨道结构轨道几何形位改变的影响,并提出钢轨变形防控措施。研究结论:(1)钢轨变形量与连续梁桥变形幅值呈正比,具有明显"跟随性";(2)连续梁桥变形导致较大扣件力集中在梁缝处;(3)无论是桥墩沉降、梁端转角还是梁体错台,都会使在桥梁变形区域边界处的钢轨产生"上翘"的现象,且"上翘"值与桥梁变形幅值呈正相关,合理控制变形区域边界处的钢轨上翘,可保证线路高效安全运营;(4)本研究结论可为防治轨道几何形位演变提供理论依据。

Influence of the Typical Deformation of Continuous Beam Bridge on the Track Geometry Evolution

Research purposes: Evolution of track geometry caused by the deformation of continuous beam bridge directly affects the operating speed and safety of the line. Preventing and controlling the evolution degree of track geometry is the key to ensure track regularity. Taking a 3-span continuous beam bridge with simply supported beam approach bridges and subgrade on both sides as the research object,based on the mapping analytical model for the change of track geometry due to typical deformation of continuous beam bridges that the author has established,the influence of typical deformation on track geometry change of CRTS II slab ballastless track structure,such as pier settlement,beam end horizontal and vertical rotation angle,beam body horizontal and vertical dislocation,is quantitatively studied,and the prevention and controlling measures of rail deformation are put forward. This research provides a theoretical basis for preventing and controlling track irregularity induced by deformation of bridges.Research conclusions:( 1) The deformation amount of rail is proportional to the deformation amplitude of continuous beam bridge,showing obvious " followability".( 2) The deformation of continuous beam bridge leads to the large force of fastenings concentrated in beam joints.( 3) Whether it is the pier settlement,beam end rotation or beam body dislocation,the rail at the boundary of the bridge deformation area will have the phenomenon of " upwarping",and the value of " upwarping" is positively correlated with the bridge deformation amplitude. Reasonable control of the rail upwarping at the boundary of the deformation area can ensure the efficient and safe operation of the line.( 4) The research conclusions can further provide a theoretical basis for preventing and controlling the evolution of track geometry.