A Multi-Parameter-Based Method for Risk Identification of TBM Shield Jamming

Tunnel Boring Machines are the core equipment for modern tunnel construction, yet early warning of shield jamming risk remains a persistent engineering challenge. This study proposes a full process identification method for TBM shield jamming risk and establishes a complete identification and early warning framework that applies to both excavation and shutdown states. The method consists of three core models. First, a jamming risk evaluation model for excavation introduces an improved thrust to cut depth index, which enables quantitative identification of jamming risk during tunneling. Second, a correlation model between top shield pressure and jamming risk supports dynamic risk evaluation during shutdown based on top shield pressure. Third, a correlation model between strain and jamming risk employs the synergy of pressure and strain monitoring to deliver continuous warning of high risk conditions. The method has been successfully applied to a tunnel project in western China, demonstrating continuous discrimination of jamming risk across operating states with good accuracy and strong engineering applicability.