Analysis And Recognition Of The Wear State Of Full-face Rock Tunnel Boring Machine Disc Cutter

Full-face tunnel boring machine (TBM) is a kind of specialized high-techconstruction equipment for large-scale excavation of rock tunnels and undergroundchannel engineering. During hard rock TBM tunneling process, cutter wearconsumption has been one of the bottlenecks that plagued the construction efficiency.In this thesis, the researches on the hard rock TBM disc cutter are conducted, in termsof the tool wear state detection theory and estimation method. Beginning from theinformation analysis of the equipment load and energy consumption, the relationshipsbetween above information and the friction and wear of cutter are established. Thenthe cutters wear state, in response to the changes of load and energy consumptioninformation, are identified and extracted. Based on these, the analysis method ofcutter wear and cutter wear real time prediction model are established and validatedby the collected engineering excavation data.In this paper, the forces on constant cross section (CCS) disc cutter are analyzed,and the load distribution on cutter and rock contact arc length is researched throughmechanical analysis and finite element numerical simulation. As a result, the model ofapproximate parabola distribution of distributed load is presented, which is validatedby the relative experimental results and actual engineering load data. The analysismethod to detect disc cutter wear is established according to the correlation betweenworking parameters and disc cutter geometry parameters. Based on above researches,the relationship between hard rock TBMs working parameters, rock mass parametersand disc cutter geometry is further investigated. Combined with above research results,the specific energy formula is proposed, and the energy method to estimate the wearextent of disc cutter is established. Furthermore, above specific energy formula andenergy method are validated by Turkey Kozyatagi-Kadikoy (Ko-Ka) subway tunneland Qinling Mountains tunnel.According to the analysis of equipment energy consumption and its changeinformation, the influences of friction energy on TBM torque energy and thrust energyare studied, the interrelation between torque energy and thrust energy is analyzed, andthe cutter wear state is extracted from the response to changes in the energyconsumption information. Then the cutters wear state equation is established, and the criteria for upper and lower limits of the tunneling energy consumption are proposed.According to the macro analysis, SEM analysis and surface metallographic analysis ofthe failure surface of disc cutter, considering the main factors of the tool surfacecontact fatigue wear, the relationship between friction energy and friction volume isanalyzed, and the abrasion cutter change model suitable for engineering applicationsis established. At last, the validity of the abrasion cutter change model is confirmed byYintao project9#tunnel.