Abstract:

Due to the different cutting mechanisms and configurations of the cutting tools in soft soil stratum and the rock stratum, the adaptive configuration of the cutting tool and the replacement safety of the worn tool in different geologies, especially in complex geology, are the technical problems encountered during largediameter shield tunneling. The selection and configuration of the cutting tools in soft soil and hard rock composite strata are analyzed by taking largediameter slurry shield used in Yangtze Rivercrossing tunnel on Wuhan Metro Line No. 8 for example; the design concept of composite cutterhead is innovatively adopted; the interchange technology of hob cutter and toothed cutter under atmospheric condition is developed and carried out; and the cutting tool configuration schemes are given for different geological conditions， By adopting the abovementioned measures,the service life of the cutting tool is prolonged; the cutting efficiency of the cutting tool is improved; the construction risk is reduced; and the successful shield tunneling in complex strata is realized.

Key words: largediameter shield, complex geology, cutterhead and cutting tool selection, cutting tool replacement under atmospheric condition, cutting tool adaptability configuration