插入道岔施工对运营高速道岔锁定轨温变化影响试验

Experiment on the impact of turnout inserting construction on the stress-free rail temperature of operating high-speed turnouts

为研究插入道岔施工(Turnout Inserting Construction,TIC)对既有高速道岔锁定轨温(StressFree Rail Temperature of Existing high-speed Turnout,SFRTET)的影响,提出基于双向应变法的锁定轨温变化测试方案,推导不同因素影响下的锁定轨温变化测量原理,确定监测数据的处理方法,并开展道岔锁定轨温变化现场试验研究.研究结果表明:基于锁定轨温变化监测方法确定的传感器安装时轨温与实测数据差异仅1.4%,验证了测试方案的合理性和数据处理方法的正确性;高速道岔的锁定轨温会受插入道岔各工序施工的影响,其在轨道结构拆除、轨道结构施工、道岔形位精调和工电联调3个工序中表现出显著的动态变化特征,即锁定轨温经历多次循环变化才达到稳定状态;既有高速道岔锁定轨温受侧股钢轨重新焊接施工影响最为显著,尤其是靠近焊接位置的侧股钢轨,其锁定轨温变化达12.87℃,建议侧股钢轨重新焊接工序尽可能选择在轨温接近既有道岔原锁定轨温时开展.

To investigate the impact of Turnout Inserting Construction(TIC)on the Stress-Free Rail Temperature of Existing high-speed Turnout(SFRTET),a scheme to measure the change in SFRTET based on the bi-directional strain approach is proposed.The measurement principle of SFRTET changes caused by different factors is derived,and the data processing method for monitor⁃ing the change in SFRTET is determined.Field experimental research on the change of SFRTET is conducted.The results show that the difference between the rail installing-sensors temperature ob⁃tained from the SFRTET monitoring data and the directly measured data is only 1.4%,validating the rationality of the measuring principle and the correctness of the data processing method.The SFRTET of high-speed turnouts is influenced by each stage of TIC,exhibiting significant dynamic change characteristics during the stages of demolishing track structure,track structure construction,fine adjustment of turnout geometry,and integrated commissioning.This indicates that the SFRTET would undergo certain cyclic changes before reaching stability.The SFRTET of existing high-speed turnouts is most significantly affected by the re-welding of the branch rail,especially the branch rail near the welding position,with a temperature change of up to 12.87°C.It is recommended that the rail welding construction should be carried out when the rail temperature is close to the original SFRTET.