铁道建筑

对郑渝高铁大跨连续刚构拱组合桥开展了桥上小阻力扣件测试、钢轨伸缩调节器状态监测、桥上无缝线路锁定轨温测试、线路服役性能动态检测等研究。结果表明：大跨连续刚构拱组合桥上无缝线路总体状态良好，各项监测指标正常；现场铺设的W300-1型小阻力扣件总体使用状况良好，但需关注梁端轨下垫板的纵向窜动问题；现场钢轨锈蚀严重，建议进行定期的钢轨维护和锈蚀处理，保持扣件与钢轨之间的良好接触和摩擦因数；三座典型大跨桥中全桥铺设小阻力扣件的两座实际锁定轨温低于台账记录值，这与连续刚构拱组合桥上梁轨相互作用影响有关，在主桥跨中位置无缝线路纵向力处于较低水平；结合线路服役性能动态检测结果，线路TQI值、轨距、水平、高低、轨向、三角坑等线路几何状态参数变化均满足现有规范要求。

Research has been conducted on the small resistance fastener testing, rail expansion joint monitoring, stress-free temperature testing, and dynamic performance testing of the Zhengzhou-Chongqing high speed railway longspan continuous rigid frame arch composite bridges. The research results indicate that the overall condition of the CWR(Continuous Welded Rail) track on the long-span continuous rigid frame arch composite bridges ars good, and all monitoring indicators are normal. The W300-1 type low resistance fasteners laid on site are generally in good working condition, but attention should be paid to the longitudinal movement of the beam end rail pad. Due to severe corrosion of the rails, it is recommended to conduct regular maintenance and rust treatment of the rails to maintain good contact and friction coefficient between the fasteners and the rails. The tests show that the actual stress-free temperature of two of the three typical long-span bridges with low resistance fasteners installed on the entire bridge is lower than the recorded stress-free temperature in the ledger.This is related to the interaction between the beam and track on the continuous rigid arch combination bridge. The longitudinal force in the mid-span of the main span is at a relatively low level. Based on the dynamic testing results of the line's service performance, the changes in the geometric state parameters of the line, such as TQI(Track Quality Index), track gauge, level, height, track orientation, triangular pits, all meet the requirements of existing specifications.