Recently, the "Yong'an" shield machine on the Guifengshan Tunnel of the Zhuhai-Zhaoqing High-Speed Railway completed a mode switch, transitioning from earth pressure mode to TBM mode.

The mode-switching location of the "Yong'an" shield machine was inside the Guifengshan Tunnel, at a burial depth of approximately 53 m. The surrounding rock of the tunnel section is weakly weathered gneiss. The in-tunnel mode-switching method was adopted, facing multiple difficulties such as enormous schedule pressure, confined working space, large tunnel burial depth, insufficient reference experience, and complex technical issues. By sorting out the operation process, introducing mechanical assistance, and advancing multiple procedures in parallel, the project department efficiently and orderly completed the dismantling, maintenance, replacement, and installation of major components, effectively shortening the mode-switching time and improving the mode-switching efficiency, completing the mode switch in only 19 days.