Earth Pressure Balance (EPB) TBM
EPB TBM is a type of closed shield TBM. When boring, its cutterhead will rotate and cut through the ground. The mucks cut will enter soil chamber. When the chamber is full, the earth pressure therein will be in balance with the earth/water pressure on cut face, which further makes the cut face and the bulk head be in balance (in stable state).
Zhengzhou Metro Project, China (fine sand, silt)
CREG supplied fifteen TBMs to Zhengzhou Metro. Geology thereof is featured by fine sand and silt. TBM CREC-02 was used in Metro Line 1 and bored through Jinshui River, Tiexi Community and Zhengzhou Railway No.6 Middle School where seated clusters of old brick masonry and concrete structures/ buildings. Maximum monthly advance rate made by this TBM reached up to 450m. TBM CREC-31 was applied in Zhengzhou Metro Line 2 and maximum monthly advance rate it reached is 454.5m.