Abstract: In this paper, the cutting mechanism of shield cutter in different strata is analyzed based on case study of typical largediameter underwater shield tunnel projects, the cutter configuration technology of largediameter shield in different complex strata with high water pressure are introduced, and the advanced technologies of shield cutterhead configuration and cutter replacement for underwater largediameter shield are systematically summarized. And then, based on the characteristics of river bottom, i.e. high water pressure, strong water permeability and instability, the technology of cutter replacement under atmospheric pressure and chamber opening under pressure is introduced. Finally, some technical issues of largediameter shield tunnel projects under construction and planning which should be deeply studied are put forward.

Key words: underwater tunnel, high water pressure, largediameter shield, cutterhead configuration, cutter replacement