基于DIC技术的隧底补强变形监测与控制

DIC-based Monitoring and Control of Tunnel Deformation during Tunnel Bottom Reinforcement

北方某货运铁路隧道整体道床由于受冻胀作用和地下水冲蚀出现裂缝,造成轨道整体下沉,对列车的行车安全造成了一定的安全隐患。采用"锚注一体化"的快速修复方法填充整体道床底部缝隙,可有效加固整体道床,但注胶过程中会引起轨道竖向变形。为防止轨道变形过大,需对轨道变形进行实时监测。采用DIC实时变形监测系统对轨道竖向变形进行实时监测,监测结果表明:在注胶过程中,当整体道床底部存在非贯通裂隙时,轨道在注胶压力的作用下抬升,当达到1mm的警戒位移时,停止注胶,轨道缓慢下降;当整体道床底部存在贯通裂隙时,出现渗水现象,轨道在注胶压力作用下缓慢且均匀地抬升;当达到1mm的警戒位移时,停止注胶,轨道缓慢下降。通过DIC实时变形监测系统捕捉了轨道在注胶过程中的竖向变形规律,为后续的工程实施提供有力保障。

Due to cracks caused by frost heaving and ground water erosion, the integrated ballast bed of a freight railway tunnel in North China was troubled by subsidence of the track, which posed a safety hazard to the train operation safety. The ＂anchoring-grouting＂ fast-repair method can be used to fill the cracks at the bottom of the integrated ballast bed, which can effectively reinforce the ballast bed. However, vertical deformation of the track may be caused during the grouting process. In order to prevent too large a deformation of the track, realtime monitoring of track deformation is needed. In this study, DIC real-time deformation monitoring system was used to monitor the vertical deformation of the track in real time. The results show that during the grouting process, the track was lifted under the grouting pressure when there was an intermittent crack at the bottom of the integrated ballast bed. When the displacement reached 1 mm, a warning triggering value, the injection was stopped and the track slowly descended. When there was a continuous crack, water seepage occurred, the track was elevated slowly and uniformly under the grouting pressure. When the displacement reached 1 mm, the injection was stopped and the track slowly descended. The DIC real-time deformation monitoring system captured the vertical deformation rules of the track during the grouting process, and the study provided strong support for subsequent project implementation.