Abstract:

Blockings usually occur to cutterhead and cutter box during tunneling of composite earth pressure balance (EPB) shield. As a result, the rationalities of cutterhead and cutter arrangement are studied in terms of cutting effect; the dynamic cutting simulation method of cutter group and disc cutter group is adopted; the evaluation indices for soil mass variation and cutterhead loading are put forward. The simulation results show that: 1) In soft soil stratum, the cutting effect of the cutter group with inner angle is obviously better than that without inner angle. 2) The small cutter overlap should be adopted when tunneling in soft stratum; and large cutter overlap should be adopted when tunneling in hard stratum. The study of cutter group layout can provide a method to solve practical engineering problems and the finite element simulation results can provide reference for the design of cutterhead and cutter group of EPB shield.

Key words: multiple geological conditions, composite earth pressure balance (EPB) shield, cutterhead, cutter layout, dynamic cutting simulation, cutter group