Assertion: reamed bore | /r/HasProperty | excavated in this method
Facets:
value: by extending the extendable wing bits
type: MANNER
Source sentences:
text: In this method, however, since the under-reamed bore is excavated by extending the extendable wing bits horizontally by hydraulic cylinders without moving the wing bits downward, it is very difficult to form a stable impermeable surface layer preventing water from penetrating into the soil wall of the excavated bore and preventing lumps of soil from being dislodged therefrom, and additionally a relatively great torque is required to excavate the under-reamed part of the bore.