Abstract:

The shield used in Phase 1 of Ningbo Metro Line No. 5 has to cross consolidated clay with plastic drainage plates with oblique angle of 68° and length of 40 m when crossing underneath highway roadbed. The highway roadbed would settle and the shield would be jammed in case of improper treatment. In order to prove the feasibility of the shield cutting and direct crossing and study the cutter selection and parameter optimization, some experiments on drainage plate breaking of consolidated clay with different types of cutters and tunneling parameters are carried out based on TBM boring mode experimental platform. The results show that the shield direct cutting plastic drainage plate in consolidated clay is feasible under the conditions of rational cutter selection and optimal parameter settings. The experiments provide basis for the construction of Ningbo Metro has provided experimental reference, and can further provide reference for shield tunneling and design of similar projects in the future.

Key words: metro shield, consolidated clay, drainage plate, breaking method, cutter optimization, tunneling parameter