Volume 02 Issue 09-2022
35
American Journal Of Applied Science And Technology
(ISSN
–
2771-2745)
VOLUME
02
I
SSUE
09
Pages:
35-38
SJIF
I
MPACT
FACTOR
(2021:
5.
705
)
(2022:
5.
705
)
OCLC
–
1121105677
METADATA
IF
–
5.582
Publisher:
Oscar Publishing Services
Servi
ABSTRACT
The article deals with the construction of saline regions of the Republic of Uzbekistan.
KEYWORDS
Salinization, saline soil, characteristic properties of saline soils, melioration, soil deformation, leaching, suffosion
sedimentation, stratification, etc.
INTRODUCTION
Saline soil
Soils containing easily soluble mineral salts in the entire
composition or in its composition in quantities harmful
to plants (more than 0.1 - 0.3%). Salinity under certain
conditions can be a variety of different soils. The
process of salt accumulation is known as salinization.
Salinization can be different, that is, due to natural
processes (weathering of minerals, impulverization -
the bringing of salts by the wind) and through artificial
irrigation processes, drained, etc. According to the
degree of salinity, soils are divided into slightly -
medium, strongly and very strongly saline.
Research Article
ADDITIONAL MEASURES FOR DESIGN AND CONSTRUCTION IN SALINE
SOIL CONDITIONS OF UZBEKISTAN
Submission Date:
September 10, 2022,
Accepted Date:
September 20, 2022,
Published Date:
September 30, 2022
Crossref doi
https://doi.org/10.37547/ajast/Volume02Issue09-06
Kamildzhan Yuldashev
Lecturer at the Technical Faculty of USU, Urgench, Uzbekistan
Journal
Website:
https://theusajournals.
com/index.php/ajast
Copyright:
Original
content from this work
may be used under the
terms of the creative
commons
attributes
4.0 licence.
Volume 02 Issue 09-2022
36
American Journal Of Applied Science And Technology
(ISSN
–
2771-2745)
VOLUME
02
I
SSUE
09
Pages:
35-38
SJIF
I
MPACT
FACTOR
(2021:
5.
705
)
(2022:
5.
705
)
OCLC
–
1121105677
METADATA
IF
–
5.582
Publisher:
Oscar Publishing Services
Servi
Regardless of the chemical composition of the
compounds that flood the soil by themselves, salts can
be concentrated in a certain soil horizon. According to
the depth of the salt horizon, saline (0-30 cm),
solonchakous (30-80 cm), deep saline (80-150 cm) and
deeply saline (more than 150 cm) soils are distinguished
from the day surface. Depending on the composition
of salts in the soil, several main types of salinization are
distinguished.
a)
Chloride salinization of soils is due to the excess
content of sodium chloride and magnesium
chloride salts (NaCl, MgCl) in the soil.
b)
Sulfate salinization is caused by the accumulation
of sodium sulfate and magnesium sulfate.
(Na2SO4, MgSo4, CaSO4)
c)
Soda (carbonate) salinization is associated with the
presence in the soil of increased amounts of
sodium bicarbonate and other sodium salts
(NaHCO3, Na2CO3).
In the conditions of Central Asia, specifically the
Republic of Uzbekistan, the regions of Karakalpak A.R.,
Khorezm and Bukhara regions are located in very saline
soil zones. In thawed soil conditions, the construction
of various objects has its own characteristics. At
present, in these regions of the republic, soil
salinization is especially intensifying, since after the
drying of the Aral Sea, soil salinization is enhanced by
the influx of various salt formations accumulated on
the millionth hectares of the Aral bottom. It is difficult
to carry out construction in conditions of saline soils
due to the fact that soil deformation manifests itself
both during the construction of structures and during
operation.
At such moments, having determined the composition
of salts in the soil under laboratory conditions, having
calculated the amount of suffusion sedimentation of a
base composed of soils with easily soluble salts and
gypsum sands, performed within the zone of suffosion
sedimentation, civil and industrial buildings are erected
on these soils, but only after the desalinization of
individual layers. In the modern era of scientific and
technological progress, the organic world of greasy
soils remains a problem for many builders.
Construction in conditions of saline soils was well
known to many. Since, due to the intensive
reclamation of arid regions, large areas of previously
low-moisture saline soils turned out to be flooded,
which led to their subsidence. As a result, the
deformation of buildings, structures arose in the
constructed buildings, as well as in the newly erected
ones. Significant deformations always force builders to
look for optimal solutions in which new horizons would
open up for people. Despite the existing experience in
construction, there is not enough systematizing,
generalizing and even research data in the field of
analysis of saline soils. But construction in conditions of
saline soils is necessary, this is a requirement of the
time. Modern specialists are currently offering
solutions to these problems - to reduce construction
risks and get rid of unnecessary cataclysms.
Construction in the conditions of saline soils, in some
cases, was carried out without special instructions in
the project for the performance of construction work
in saline soils. Because of this, in the solid consistency
of soils, deformations of the bases were especially
pronounced (in the form of a sharp deformation of
buildings) when the soils were soaked. This is
explained by the fact that when soils are saturated
with water and salts are dissolved, the strength and
interconnection of individual particles sharply
decrease, as a result of which the strength
characteristics and the value of the total deformation
modulus change.
Volume 02 Issue 09-2022
37
American Journal Of Applied Science And Technology
(ISSN
–
2771-2745)
VOLUME
02
I
SSUE
09
Pages:
35-38
SJIF
I
MPACT
FACTOR
(2021:
5.
705
)
(2022:
5.
705
)
OCLC
–
1121105677
METADATA
IF
–
5.582
Publisher:
Oscar Publishing Services
Servi
The process of dissolution of salts in soils occurs very
quickly (especially when easily soluble salts interact
with hot water), as does suffusion subsidence, which
occurs within a short period of time. When designing,
if the designer does not receive information about the
specifics of saline soils, for which norms and
recommendations for conducting engineering and
geological surveys have not yet been developed, at
construction sites composed of saline soils, then
measures are taken only to protect the foundation
from
possible
corrosion,
and
the
design
documentation contains information on the need to
protect the surface of the instructions for concrete
foundations. That is, construction in conditions of
saline soils is carried out according to the same
technological schemes as construction on ordinary
soils. As a result, during construction work, surface and
groundwater often flood the pit and enter the backfill
material of foundations and basement structures.
Builders can pump out water, but do not eliminate the
main cause of soil soaking. Because of this, during the
operation of the facility, further deformation of
structures and subsidence of buildings occurs.
In order to scientifically and competently carry out
construction in saline soil conditions, it is necessary to
reduce the compressibility of demineralized soils, and
increase the strength of the foundation by several
times, as a result, the actual precipitation of objects
and structures under construction, which on saline
soils, sometimes several times exceed the calculated
values, will stop, and possible deformations will be
prevented. If the designer is provided with reliable
information with the results of engineering surveys
and studies of the land plot, they begin to take into
account the features and distribution of contact
stresses along the sole of rigid foundations laid on
unimportant saline soils, and the possibility of
changing the contact stress diagram when flooding
saline base soils.
The difficulty of studying saline clay soils lies in the fact
that salts are present in soils in the form of separate
druses, veinlets, concentrated salt solutions and are
even
contained
in
atmospheric
precipitation
(especially in the Aral Sea zones). In order to find a
general pattern, a targeted study of saline clay soils will
help to carry out safe construction in saline soils, which
in different regions will differ significantly in
experiments, methods and ways of approaching the
solution. To date, the study of the depth of the
compressible zone at the base of the foundation on
saline soils and the change in its thickness during
watering have not been determined, methods for
constructing artificial foundations on saline clay soils
have not been developed. For this reason, construction
in saline soil conditions is carried out using pile
foundations that cope with corrosion and other
deformation phenomena in such regions. Having
calculated the expected deformation of the
foundations in saline soils, the suffusion compression
is determined and the maximum allowable value of the
deformation or insufficient bearing capacity of the
structure is calculated.
By taking water protection measures with the possible
installation of a cushion of clay soils or from a certain
thickness of compacted dune sand, cutting through
the thickness of saline soil with pile foundations, fixing
or compacting soils, preliminary stratification using
compacted dune sand for drainage, it is possible to
correctly plan construction in saline soil conditions,
while preventing the subsidence of the building under
construction and the deformation of its structures.
It means that in the conditions of saline soils on the
territory of the Republic of Uzbekistan, especially in
the northern regions, underground groundwater has a
Volume 02 Issue 09-2022
38
American Journal Of Applied Science And Technology
(ISSN
–
2771-2745)
VOLUME
02
I
SSUE
09
Pages:
35-38
SJIF
I
MPACT
FACTOR
(2021:
5.
705
)
(2022:
5.
705
)
OCLC
–
1121105677
METADATA
IF
–
5.582
Publisher:
Oscar Publishing Services
Servi
periodic nature of the speed of movement and
direction. Since spring watering for washing land
enhances the flow of these waters. These
underground saline water currents carry a very large
amount of sodium salts. Water currents in some places
washes, and in some places it salts the soil. Clayey
ground rocks have such a characteristic ability that
when wet with saline waters they contain some part of
the salts, and are difficult to wash. Therefore, such soils
are washed 2-4 times under high pressure of non-saline
water in order to dissolve the salts. And barkhan sands,
when washed from salinization, do not leave part of
the salts in themselves like clay soils. Therefore, in the
construction of buildings and structures, it is necessary
to foresee and take into account these useful
properties of dune sands. Especially the base
(horizontal sole part) and the vertical underground
structures of the underground parts of the building
must be contacted with compacted sand with a
thickness of 20 to 40 cm before backfilling. These
measures reduce the risk of prolonged contact of
underground parts from exposure to salts.
Construction in the conditions of saline soils is a very
complex work, requiring the use of specific
scientifically sound, economically inexpensive and
effective measures. Before builders and designers and
scientists working in saline soil conditions, there are big
tasks that must be successfully solved.
REFERENCES
1.
Guidelines for the management of saline soils.
R.Vorgas, E.I. Pankova, S.A. Balyuka, P.V.
Krasilnikova.
