Civil Engineering Reference
In-Depth Information
Figure 19.18
Change of stress across a stress fan for drained loading.
Figure 19.18 shows a stress fan and the correspondingMohr circles for drained loading.
As before there will be a great number of additional radial discontinuities and Mohr
circles between the outermost ones. Note that the limits of the fan zone are defined by
θ
45
◦
+
1
2
φ
c
. From Eq. (19.24), the change of stress across a discontinuity can
=
θ
b
=
a
be written as
d
s
s
=
ρ
2 sin
δθ
sin
(19.37)
δθ
+
ρ
)
cos(
ρ
=
φ
c
and from Eq. (19.37),
As
δθ
→
0, from Eq. (19.22) we have
d
s
d
2
s
tan
φ
c
θ
=
(19.38)
