This research aims to study the effect of stone columns on
the change of settlement in clay soils.
We defined the stone column and its uses , We explained
the transfer mechanism of load to the soil .
We spoke about important theories which discus
s the
settlement of clay soil reinforced by stone columns (Priebe
theory) .
we used the unite cell idea to study the settlement behavior
in the clay soils affected by the stone column to generalize
the study on unlimited loading area of clay soils , so we has
been defined some of the basics which relate to the unit cell
.We made a group of tests on a small model to define the
settlement of clay soils in the case of absence of stone
columns and in the case of presence of stone columns with
different diameters to know the change of the settlement
with the change of area replacement ratio inside the unite
cell , then we compared the laboratory tests results with the
results of Priebe (1995) .
This research is done in an experiment by plaster in the
circumstances of Homs. The aim of this paper to study the effect of
adding four different levels of phosphogypsum as much as (0.00,
6.72, 13.44, 20.16)ton / hectare (three replicates for eac
h treatment)
on bulk density and structure stability for clay soil has taken from
(Kattina).
The results showed improvement in the stability of the structure of
soil specially (0.25-1)mm, increasing in aggregation degree ,
increasing of the rate of total porosity ,air filled porosity in
comparison to the control at the two levels(13.44, 20.16)ton/hectare
and also by increasing the added level . Whereas the dispersion
ratio , and Bulk density were decreased when increasing the level
of phosphogypsum at the same two levels.
The main achieved results in this study showed , a significant
increase in aggregation degree in the soil when increasing the ratio
of the added phosphogypsum at the levels( 6.72, 13.44, 20.16) in
comparasion with control .
In other way the dispersion ratio was decreased and had negative
relationship when increasing the level of the added
phosphogypsum in comparasion with control .
This research was conducted in 2016c, at the Zahid Western
Research Station in Akkar Plain region of Tartous Governorate, the
objective of this research is study the effect of non-conventional
organic waste (compost of garbage, sewage sludge) and
cow
manure on the physical properties of clay soil in the region. Wastes
was added to the soil at a rate of (0 - 10 - 20 – 30) t/ha, in order to
determine the effect of the difference in the quantity added on
physical properties of the soil and peanut productivity.
