1524
Proceedings of the 18
th
International Conference on Soil Mechanics and Geotechnical Engineering, Paris 2013
underestimated values of mechanical characteristics and
uneconomical design decisions.
Now researches on bearing ability soil gravel, and also
on influence of the sizes of fractions is a lot of (L.A.Avakjan
1981, V.I.Feodorov 1973). Researchers are conducted on shift
devices and in field conditions. However similar researches are
very labor-consuming because of the big extent of rocky
separateness and volumes of tests, need of use of large-scale
devices.
In laboratory of the Kazakh Leading Architectural and
Construction Academy (the city of Almaty, Kazakhstan) are
conducted researches on definition of influence of diameter of
fraction and percentage of inclusions on indicators of durability
of soil. Researches were conducted on special option of the one-
plane device of a design of the Moscow Engineering
Construction Institute (Figure 1) (V.A.Khomyakov 2007), and
also in an experimental tray with different structures of soil
mixes.
The area of a sample of the shift device is equal 100
cm
2
, sample height 8,1cm. Tests are dried with different
compositions of soil with filler fractions from 2 to 20 mm. Tests
are carried out on compositions of soil with the maintenance of
large fractions 25, 50, 75 percent. At test on the shift device
resistance to shift of soil was determined by the kinematic
scheme after preliminary consolidation of samples by vertical
loading before conditional stabilization. Horizontal deformation
was put and the shifting effort was registered. Percentage of
large fractions and filler in mixes was established by results of
definition of grain structure. Results of tests were subjected to
statistical processing.
Figure 1. The general view of the shift device
In Table 1 results of tests of influence of inclusions on durability
gravel of a ground for tests other authors (L.A.Avakjan
1981,V.I.Feodorov 1973) and KazGАCА are given.
Research of influence of filler on properties of a ground
has shown, that at increase of number of plasticity of clay filler
of value of a corner of internal friction are reduced, and specific
coupling grow (V.I.Feodorov 1973). The increase of the
maintenance of a sandy filler up to 25 % raises value of a corner
of internal friction and lowers value of specific coupling (
V.I.Feodorov 1973,V.A.Khomyakov 2007).
It is necessary to note, that results of definition of a
corner of internal friction and specific coupling for artificial
mixes tested DalNIICA (L.A.Avakjan1981) and in laboratory
KazGASA on shift devices of the different sizes appeared
comparable, and confirm, that increase of the maintenance of
large fractions more than 25 %, irrespective of a kind of a filler,
results in increase of durability of the basis.
For obtaining fuller data on properties of soil, in
laboratories of KazGACA on the special tray, imitating seismic
impacts on the soil massif, tests on stability of boards of the
ditches put by loams (Figure 2) were carried out.
The tray represents a rectangle 1200 mm long, 200 mm
wide and 800 mm high. The tray is in the middle divided into
two parts by a partition. Forward wall of a tray transparent of
plexiglas, back and lateral walls wooden also are strengthened
by metal. Mobility of the stand is provided by means of four
axes with wheels on ball-bearings. Seismic loading is put by
action of the squeezed spring. Parameters of influence are
registered special control measuring equipment.
Table 1. Influence of a filler on durability of the characteristic of a
ground
The maintenance gravel of a
ground, %
The name of a
ground and the
size of fractions
The size
of
fraction
of a
filler or
consiste
nce
The
char
acter
istic
of a
grou
nd
25
35
50
70
75
1
2
3
4
5
6
7
8
с,
кPа
1
-
45
-
1
Gravel a ground
(fractions from
10-20 mm)
0,25÷2
mm
,
48
-
52
-
63
с,
кPа
1
-
1
-
1
Gravel a ground
(fractions from
5-10 mm)
0,25÷2
mm
,
42
-
42
-
60
с,
кPа
2
-
21
-
34
Gravel a ground
(fractions from
2- 5 mm)
0,25÷2
mm
,
41
-
44
-
52
с,
кPа
11
10
7
5
-
Sandy loam
plastic
consiste
nce0
J
L
≤0,75
,
38
42
45
47
-
с,
кPа
41
35
27
20
-
Loam
semi-
firm
consiste
nce0
J
L
≤0,25
,
27
34
39
45
-
с,
кPа
50
43
34
25
-
Clay
semi-
firm
consiste
nce0
J
L
≤0,25
,
18
24
33
41
-
The note - the maintenance of diameter gravel of inclusions
(%) is established by results of definition of grain structure. Thus
particles are larger 2mm carry to inclusions, particles less 2mm - to a
filler.
In laboratory researches the soil model which structure
consists of three components was used: sand – 80%, grated
small polyfoam – 10%, veretenny oil – 10%. Density of model
of soil -1450 kg/m
3
. According to the characteristics the model
of soil is similar to macro porosity loam. External loading
modeling weight a number of the located building, it was put by
the weight of a set of weights. Weights are installed on a
rectangular platform of 200х200 mm. Test objective was
determination of stability of boards without actions for fixing of
soil when developing ditches. To determine the maximum
height of a slope with which stability is provided with a corner
of a natural slope. Stability increase in case of strengthening of
a slope of a ditch by soil anchors. Anchor was modeled by a
metal wire with seal to the massif. Anchor was established in
two ranks, the retaining wall is modeled by a wooden plate.
As a result of tests it is received that application of
