高速铁路无缝线路状态演变机理及规律研究

The states of the continuously welded rail (CWR) track are essential to the high-quality running of the train. There are poor states in some sections of Chinese CWR, but the knowledge of evolution mechanisms and laws of CWR are insufficient, which are highly concerned by the railway departments of China. This project studies the typical structures and components with poor quality state. Through theoretical analysis, experimental research and numerical simulation, firstly, the main factors affecting the CWR quality state will be defined; secondly, the evolution mechanisms due to the interaction between CWR on ballastless bed and multi-span continuous beam bridge, the deformation of CWR, the states of ballastless bed and the welded turnouts will be revealed; thirdly, the evolution laws of the CWR quality state under the complex conditions will be obtained; finally, the following will be put forward: (1) the maximum temperature span, the set conditions and methods for expansion rail joint, and the limited longitudinal stiffness of the bridge pier for long multi-span continuous beam bridge, (2) the criterions and allowable limits for deformation of CWR on various track structures, and those for the various deterioration indicators of the ballastless bed and the welded turnout, and (3) the quality control methods of the CWR state on various infrastructures. The results will provide important theories for improving the design codes and maintenance rules for the CWR in high-speed railway. The results are also very significant for ensuring the smooth and steady state, as well as the safe and comfortable operation of a high-speed train.

高速铁路无缝线路质量状态是保证列车高品质运行的关键，我国对其演变机理及规律认识仍不充分，个别地段无缝线路质量状态不良，受到铁路部门的高度关注。项目以无缝线路质量状态不良的典型结构和部件为研究对象，采用理论分析、试验研究、数值仿真相结合的研究方法，明确影响无缝线路质量状态演变的主要因素；揭示复杂条件下无砟无缝线路与多跨长联连续梁桥相互作用、长钢轨变形、无砟道床及无缝道岔状态的演变机理；获取复杂条件下无缝线路质量状态演变规律；提出（1）多跨长联连续梁桥极限温度跨度、钢轨伸缩调节器的设置条件和方法、以及桥梁墩台纵向刚度限值，（2）不同轨道结构长钢轨变形、无砟道床及无缝道岔劣化指标的评判准则、允许限值，（3）不同下部基础无缝线路质量状态的控制方法。研究成果为完善高速铁路无缝线路的设计规范和养护维修规则提供重要理论支撑，对保证高速铁路无缝线路的平顺、稳定状态以及高速列车高品质运行具有十分重要的意义。

高速铁路无缝线路状态是保证列车高品质运行的关键，受到铁路部门的高度关注。项目采用理论分析、试验研究、数值仿真相结合的研究方法，围绕复杂条件下无缝线路与桥梁相互作用、长钢轨变形、无砟道床以及无缝道岔的状态演变及规律开展研究，获得了以下重要成果： .（1）现场测试表明典型地区桥上CRTSⅡ型无砟轨道温度场具有明显的时空特性分布规律。（2）基于实桥参数的无缝线路与桥梁相互作用数值仿真，提出了不同轨道型式与扣件阻力的连续梁温度跨度限值，大跨度桥梁轨道伸缩调节器的设置原则与最佳方式，发现大跨度连续梁桥固结机构处CA砂浆处于薄弱环节。（3）获得周期性温度作用下，长钢轨横向、纵向、垂向位移周期性变化特征，并建立了钢轨横向累积变形与时间的关系表达式。（4）获得了钢轨等效温升幅度、钢轨初始不平顺、钢轨初始弯曲半波数、扣件横向刚度、曲线半径、列车横向荷载等参数对长钢轨横向变形的影响规律。（5）揭示了桥隧过渡段无砟轨道钢轨纵向爬行机理以及高速铁路基础变形对钢轨变形的影响机理。（6）发现气候环境及施工温度对无砟道床状态演变有一定的影响，而无砟道床配筋率的影响较大。（7）在研究复杂荷载组合下桥上纵连板式无砟道床服役状态演变规律、列车-无砟轨道-桥梁耦合系统动力特性及无砟轨道疲劳寿命的基础上，提出了施工温度、无砟轨道配筋率的建议，以控制无砟道床状态演变。 .（8）发现反复荷载作用下的扣件阻力弹塑性特征明显，高速铁路道岔间隔铁、限位器阻力性能具有非线性特性，以及低温高寒条件下，扣件阻力下降的较为明显。（9）循环温度及列车周期荷载作用下，无缝道岔纵向受力变化规律较为复杂，产生一些影响道岔使用性能病害。（10）研究了道岔典型伤损的标准及允许限值。研究成果为完善高速铁路无缝线路的设计规范和养护维修规则提供重要理论支撑，对保证高速铁路无缝线路的平顺、稳定状态以及高速列车高品质运行具有十分重要的意义。