Geoscience Reference
In-Depth Information
Figure 7.43
Pressure vs. settlement curves; different shear strengths and different geogrid encase-
ment stiffness; column diameter
=
0.5m,
s
/
d
=
3 (NE
=
No encasement) (
after
Prasad
et al.
,
2012).
Figure 7.44
Pressure vs. settlement for single column and a group of columns, entire area loaded,
s
/
d
=
3(
after
Prasad
et al.
, 2012).
stone column reduces as the stiffness of the encasement increases. This implies that the
capacity of encased columns is almost independent of the strength of the surrounding
soil for extremely stiff geogrid encasements. Murugesan and Rajagopal (2006, 2010)
have also observed that the stiffness of the encasement plays an important role in
reducing the bulging of the columns, thus leading to higher bearing capacity of the
columns.
Figure 7.44 shows a comparison of axial stress versus settlement behaviour of a
group of seven columns and of a single column when the entire area is loaded based on
finite-element analysis for
s
/
d
3. It can be seen that the behaviour of a single column
and a group of columns is almost comparable.
=
