Abstract: Traditional welded lifting lugs in shield cutterhead have various disadvantages such as inefficiency, high labor intensity, elevated costs, and environmental pollution. Therefore, a novel type of detachable lifting lug was designed and developed based on the lifting operations during cutterhead production, installation, and removal, as well as its structural characteristics. Primary parameters of this lifting lug are designed based on the actual dimensions of conventional 6－7-m soft soil cutterheads. Through mechanical analysis of the cutterhead under vertical and horizontal lifting conditions, a simplified mechanical model for this lifting lug is established. Structural strength calculations indicate that the stress at all critical sections remains below 50 MPa during vertical lifting, with the maximum stress reaching approximately 87 MPa in horizontal lifting scenarios. ANSYS simulation software further analyzes stress distribution during various lifting scenarios, revealing that stresses excluding localized areas near stress concentration points are below 80 MPa. Mechanical calculations and simulations demonstrate that stresses on the novel detachable lug under all lifting conditions are substantially lower than the material′s allowable stress, confirming its structural adequacy for cutterhead lifting. This innovation is successfully applied in Shanghai′s hard X-ray project. On-site removal of the lugs before shield launch takes merely 1 hour, while traditional welded lugs take 2－4 days. The novel detachable lifting lugs avoid welding, damage detection, cutting, and polishing of the traditional welded lugs. This result in markedly construction efficiency and lower cost.

Key words: shield cutterhead, detachable lifting lug, simulation analysis, lifting operation