Pile Design and Construction Practice, Fifth edition

Hinged cutters

Profile of

completed base

Housing

Borehole

casing

Kelly

(a) (b)

Figure 3.28Types of drilling tools (a) Standard auger (b) Rock auger (c) Coring bucket (d) Bentonite
bucket (e) Chisel.

(a) (b) (c)

(d) (e)

Figure 3.29Under-reaming tools (a) Bottom hinge (b) Top hinge.