Dynamic analysis of cutting RC structure with shield disc-cutter: Insights from the coupled simulation and laboratory test verification

During shield tunneling in densely populated urban areas, shield machines may unexpectedly encounter obstacles such as reinforced concrete (RC) structure. Cutting through RC structure with a shield machine presents significant challenges due to potential cutter damage and reduced cutting efficiency. In this study, dynamic analyses of cutting RC structure via disc-cutter were performed based on the finite element method-discrete element method (FEM-DEM) coupled approach. In FEM-DEM coupled model, the mechanical behaviour of concrete is represented using DEM, while the influence of the rebar in the concrete is accounted for through FEM. And the precision and dependability of the simulation results were validated through the laboratory experiments. Overall, the numerical outcomes agreed well with the experimental data. Furthermore, a parametric study was conducted, and the effects of the shield working parameters and the geometric configurations of disc-cutter on the cutting performance of the disc-cutter were investigated, respectively. Through the parametric analysis, it is recommended that the shield machine adopts a tunneling pattern with low penetration and medium rotational speed in actual project when cutting the RC structure. The findings of this study may serve as valuable references for cutting RC obstacles with disc-cutters in future applications.