Civil Engineering Reference
In-Depth Information
Figure 23.7
Capacity of pile groups.
shallow foundations described in Chapter 22 and the shear stresses on the sides of the
block are calculated assuming that the ultimate shear stresses developed correspond to
the strength of the soil.
23.6 Summary
1. Piled foundations are used to lower the foundation into soil which is stiffer and
stronger. The load capacity of a pile arises from base resistance and shaft friction.
2. Base resistance of a single pile is given by
q
b
=
s
u
N
c
(23.3)
q
b
=
σ
v
N
q
(23.4)
for undrained and drained loading respectively.
3. The shaft friction of a single pile is given by
τ
s
=
α
s
u
(23.6)
