赣江特大桥跨九龙大道道岔连续梁拱桥轨道服役状态监测研究

Research on Track Service State Monitoring of Turnout Continuous Beam Arch Bridge of Ganjiang Super Major Bridge Crossing Jiulong Avenue

大跨度桥铺设无砟轨道和无缝道岔技术难点多、结构间相互作用复杂,是高速铁路轨道结构的薄弱环节,为保障列车安全运营,需对轨道结构进行长期实时监测。以赣江特大桥跨九龙大道道岔连续梁拱桥上无砟轨道为监测对象,建立基于光纤光栅技术的高速铁路大跨度桥上轨道结构监测系统。通过对监测数据分析,得出炎热季节(7月)月最高道床板温度高于月最高气温约11℃,月最高底座板温度与月最高气温接近;桥梁梁缝位移变化峰值滞后于当日气温峰值,且桥梁梁缝位移变化与气温变化呈现明显相关性;道床板钢筋应力变化较小。

There are many technical difficulties in laying ballastless track and seamless turnout on long-span bridges and the interaction between structures is complicated,which is a weak link in the track structure of HSR.In order to ensure safe train operation,it is necessary to conduct a long-term real-time monitoring on the track structure.With the ballastless track on the turnout continuous beam arch bridge of Ganjiang Super Major Bridge crossing Jiulong Avenue as the monitoring object,a track structure monitoring system on long-span bridges of HSR based on optical fiber grating technology is established.Through the analysis on monitoring data,it is concluded that the monthly maximum temperature of ballast bed slab in the hot season(July)is 11℃higher than the monthly maximum air temperature,and the monthly maximum temperature of the base plate is close to the monthly maximum air temperature;the peak value of bridge beam joint displacement change lags behind that of air temperature on the same day,and there is a significant correlation between the bridge beam joint displacement change and the air temperature change,while the stress change of steel bar of ballast bed slab is small.