Study on Reinforcing Technology System for the Overlapped Running Shield Tunnels underneath the Track Group of High Speed Railway

The large settlements of tracks will emerge due to multiple disturbances in the construction of over? lapped shield tunnels, which affects the running safety of trains. Based on the overlapped Sungang station—Honghu station shield running tunnels of Shenzhen Metro line 7 passing underneath 26 tracks of high speed railways, a reinforcement technology system consisting of“track support + subgrade reinforcement + interlayer soil consolidation +internal support of the lower tunnel”was developed. The settlements of tracks were mainly monitored automatically with manual monitoring as an auxiliary one. The results show that the maximum settlement of main track caused by constructing overlapped shield tunnels is -5.9 mm which is less than the control value of 10 mm, ensuring the operation safety and verifying the reliability and practicability of the reinforcement technology system.