Evaluation of the Adaptability of an EPB TBM to Tunnelling through Highly Variable Composite Strata

Table 7

Specifications of the cutterhead and cutters.

Property	Specification
Structural form	Hybrid (spokes + plate)
Opening ratio (central opening rate)	33% (38%)
Cutterhead specifications (diameter × length)	6,980 mm × 1,635 mm
17-inch center hob (number/height/spacing)	6/175 mm/90 mm
17-inch single-blade hob (number/height/spacing)	38/175 mm/75–85 mm
Side scraper (number/height)	12/135 mm
Scraper (number/height/width)	49/135 mm/250 mm