3169
Technical Committee 307 /
Comité technique 307
Photo 1. EPS beads mixed with sand
4.3.2 Effect of footing diameter (d) cm
Increasing rigid footing breadth causes increasing in settlement
in soil. In case of swelling soil increasing footing breadth also
causes increasing in swelling deformation even with existing of
beads. But EPS beads may be leads to decrease the percent of
the swelling and the settlement deformation as shown in
Figure 2.
4.3.3 Effect of beads density
(
B
) kN/m
3
EPS density appears to be the main parameter that correlates
with most of its mechanical properties. Compression strength,
shear strength, tension strength, flexural strength, stiffness,
creep behavior and other mechanical properties depend on the
density. Higher density leads to improve its effect. As shown in
Figure 3 increase beads density (
B
) kN/m
3
leads to decrease
each of the swelling and settlement on surface soil and circular
footing.
5
6
7
8
9
10
11
12
-1.5
-1.0
-0.5
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
Footing Size
Settlement (mm ) Swelling (mm )
footing Diameter, d, cm
soil
Footing
Figure 2.Relationship between increasing footing diameter (d) cm on
settlement and swelling for soil and footing
0.10
0.12
0.14
0.16
0.18
0.20
-0.5
0.0
0.5
1.0
1.5
2.0
Beads density effect
Settlment (mm) Swelling (mm)
Beads Density,
B
, kN/m
3
soil
footing
Figure 3.Relationship between increasing
beads density (
B
)
kN/m
3
on
settlement and swelling for soil and footing
4.3.4 Effect of beads content
(
) %
The EPS beads are highly compressible, with soft elastic nature,
having only about 1% of the density of a typical soil.
As shown in Figure 4 increase beads content (B) % leads to
decrease swelling pressure on the footing and decreases also the
swelling settlement. EPS beads particles swelling energy
absorption because of its compressible nature.
-0.2 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
Swelling (mm)
Beads content B %
soil
footing
Figure 4.Relationship between increasing
beads content (B) % on
swelling for soil and footing
4.3.5 Effect of normalized replacement thickness (t
r
/t
s
) %
Replacement layer thinness t
r
was chosen as a percentage of soil
layer thickness t
s
.As shown in Figure 5 increasing the
replaced layer improve the resistance to the swelling pressure
and decrease the swelling deformation. But economic point of
view also is important taking in to account the swelling layer
thickness. Increasing the normalized replacement thickness
(t
r
/t
s
) % leads to decrease each of the swelling and settlement on
surface soil and circular footing.
