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INCREASING THE BASE LOAD-BEARING CAPACITY STACKED WITH SOIL TYPE II ON COLLAPSIBILITY

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International Journal of Civil Engineering and Technology (IJCIET)
Volume 10, Issue 03, March 2019, pp. 750-756, Article ID: IJCIET_10_03_072
Available online at http://www.iaeme.com/ijciet/issues.asp?JType=IJCIET&VType=10&IType=03
ISSN Print: 0976-6308 and ISSN Online: 0976-6316
© IAEME Publication
Scopus Indexed
INCREASING THE BASE LOAD-BEARING
CAPACITY STACKED WITH SOIL TYPE II ON
COLLAPSIBILITY
Smolinskiy Nikolay Yakovlevich, Kharchenko Maria Sergeyevna, Kovalenko Tatyana
Anatolyevna , Bormotina Anastasia Mikhailovna, Khalitova Anzira
Rustamovna,Mukhin Andrey Valerievich and Kudinov Artyom Valerievich
Moscow State University of Civil Engineering (MGSU) National Research University, 26,
Yaroslavskoye Shosse, Moscow, Russia
ABSTRACT.
Phenomena of collapsibility should be considered as hazardous geological
processes and construction on such soils requires special attention. The main aim of
the research is to find a technical solution for eliminating collapsibility of soils under
the dense building conditions. The article presents the results of a study on the
elimination of this problem by constructing soil piles made with the help of an RG
vibratory pile driver. The results of the study are recommended for use.
Key words: collapsible soils, deformation of buildings, construction in Moldova,
dangerous geological processes, ground bed.
Cite this Article: Smolinskiy Nikolay Yakovlevich, Kharchenko Maria Sergeyevna,
Kovalenko Tatyana Anatolyevna, Bormotina Anastasia Mikhailovna, Khalitova
Anzira Rustamovna, Mukhin Andrey Valerievich and Kudinov Artyom Valerievich,
Increasing the Base Load-Bearing Capacity Stacked with Soil Type Ii on
Collapsibility, International Journal of Civil Engineering and Technology, 10(03),
2019, pp. 750-756
http://www.iaeme.com/IJCIET/issues.asp?JType=IJCIET&VType=10&IType=03
1. INTRODUCTION
On the territory of Moldova soil collapsibility is common almost everywhere. This makes
project designers use the construction areas that consist of stacked with soil type II on
collapsibility. This situation is especially up-to-date for the municipal districts of Chisinau
and the southern regions, where the thickness of the subsidence can reach 30 meters or more
[1, 2].
Analysis of literary sources and stock materials shows that, in general, construction on the
collapsing soils is carried out successfully in Moldova. Analysis of literary sources and stock
materials shows that, in general, construction on subsiding soils in Moldova is carried out
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Increasing the Base Load-Bearing Capacity Stacked with Soil Type Ii on Collapsibility
successfully. This is proved by the recommendations laid down in the regulatory documents
by such scholars as: Abelev Yu.M., Abelev M.Yu., Ananyev VP, Bondarik TK, Goncharov
VS, Klepikov SN, Kostik T .E., Kraev VF, Krieger N.I., Krutov V.I., Litvinov I.M., Lysenko
MP, Maslov NN, Mustafaev A.A., Trofimov V.T. ., as well as by the scientific research
conducted at the present time by Bogdevich OP, Bogomolov AN, Vovk VM, Olyansky Yu.I.
and etc.
Unfortunately, in the past few years, a number of cases of deformation of residential
buildings of high number of floors and collapse of slopes of pits arranged on collapsible soils
of type II have been noted in the republic. An example is the case of soil deformation at the
base of the plate of the second building of an apartment building on street Dumenyuk,
Chisinau. The draft in the corners of the building was: 94 mm and 110mm along the axes 12В and 12-D respectively. The rise of the base in the corner of the building reached 55 mm
along the axis 7.
Analysis of the design documentation and the survey of the building showed that the
foundation was made in the form of a monolithic reinforced concrete slab. The base is a
ground bed, filled out of loam, 4.9 m thick. The thickness of the subsurface soils within the
construction site is more than 18m.
In the course of studies of the physical and mechanical properties of the soil, a decrease in
the density of the ground bed was detected, first of all, it was the upper part, to its depth of
2.5 - 3.0 m. The main reason for the change in the characteristics of the ground bed was
additional moisture during the period of precipitation and snowmelt.
It should be noted that the observed deformations are uneven due to the different degree
of soaking of the ground and the initial density state, the soil moisture.
This is confirmed by the data of geodetic observations: the relative deformation along the
axis 12 in the B – D axes is 0.001, which is less than the maximum permissible. The relative
deformation along the 7-D axis has reached 0.0056, which is 1.4 times higher than the
maximum permissible values [3, Table. 72, p. 167].
The deformations that took place led to a halt in the construction of a building, the
framework of which was raised to a design height of 10 floors.
The considered case of construction on loess soils in Chisinau shows that the applied
design solutions in some cases do not allow avoiding unacceptable deformations of the
foundations, as well as buildings and structures in general.
Ground beds with a thickness of more than 3.0 - 3.5 m (sometimes up to 5.0 m) used to
eliminate subsidence of type II cannot guarantee reliable operation of the ground work.
2. RESEARCH OBJECTIVES
The analysis of literary sources has shown that, despite the significant number of scientific
works investigating the subject of collapsing soils, the number of publications on the research
on the compressed collapsing soils is limited in this region.
There was also a lack of information on the development of new methods for eliminating
the collapsing soils characteristics.
This is an additional confirmation of the relevance of the development of new methods
for eliminating the sagging and increasing the bearing capacity of the foundation, especially
in conditions of dense development.
The information mentioned above has become the basis for the research objectives, which
are the following:
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751
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Smolinskiy Nikolay Yakovlevich, Kharchenko Maria Sergeyevna, Kovalenko Tatyana
Anatolyevna, Bormotina Anastasia Mikhailovna, Khalitova Anzira Rustamovna, Mukhin
Andrey Valerievich and Kudinov Artyom Valerievich
1. To study the effect of impaction carried out with the help of an RG-vibrator, on the
strength, deformation and subsidence characteristics of soils;
2. To study the microstructure of the collapsing soils and its possible change after the
installation of the ground piles;
3. To substantiate the possibility of eliminating the collapsibility of the base by arranging
soil piles made with the help of an RG-vibratory pile driver.
3. RESEARCH METHODS AND INFORMATION BASE
In the past few years, there has been a tendency to search for new approaches to the study of
the properties of subsiding soils and the development of methods for the preparation of bases.
The authors of this article propose the use of an improved method of deep compaction
based on the use of an RG installation.
The technology for the elimination of collapsing soils using the device of ground wells is
not new [4]. In the offered method the punching of wells is carried out by a vibrating drop
under high pressure transmitted to the ground.
The method allows to reduce the vibration impact to a minimum, especially noticeable
during the “usual” punching of wells, which makes it possible to use it during the
construction close to existing buildings and structures.
In the course of the work, field and laboratory research methods were used, which were
conducted for two sites located in Chisinau:
- Section 1: construction of a residential complex on the Testemitanu street;
- Section 2: construction of a 12-storey residential building along Traian Boulevard.
The research program included: drilling boreholes; manufacture of soil piles; sampling of
rocks from the body of the pile shaft and the near-winding soil massif.
Physical and mechanical properties and subsidence were studied using standard methods
in the laboratory of the company “INGEOTEHGRUP”.
The study of the microstructure of collapsing and compacted soils was carried out using
the electron-scan microscope VEGA TS 5130 (pic.1) Preparation of soil samples for electron
microscopic studies and subsequent study were performed in the laboratory of the National
Center for Research and Testing of Materials at the Technical University of Moldova.
Figure.1. the study of the microstructure using electron-scan microscope.
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Increasing the Base Load-Bearing Capacity Stacked with Soil Type Ii on Collapsibility
For the study of compacted collapsible soils wells were drilled next to arranged ground
piles, and soil monoliths were selected for further study in the laboratory. Samples were taken
from the body of the pile shaft, as well as from wells drilled at specified distances from its
center. The conducted research allowed us to obtain new data on the physical and physic
mechanical characteristics of loess soils in a compacted state.
Table 1 and 2 show the results of laboratory studies of soils, after compaction, which
were compared with the average values of the corresponding characteristics determined in
natural conditions.
Comparative analysis showed that after compaction of the soil over the depth of the pile
shaft, the piles significantly improved the characteristics of the physic mechanical
characteristics:
- density of dry soil increased by 1.2 ÷ 1.4;
- deformation modulus by 2 ÷ 4.5;
- angle of internal friction by 1.1 ÷ 1.7;
- total grip by 2,9 ÷ 5,4;
- collapsing characteristics of soils disappeared completely.
Table 1. Comparison of physical indicators of soil
Soil type
IP plasticity
number
Turnover rate
IL
Soil density
ρ, gr/cm3
Humidity
W, %
Dry soil density
ρd, gr/cm3
Loam in a natural
occurrence
12
˂0
1,57
12,0
1,39
Compacted loam
8 – 12
˂0
1,88 – 2,09
8,0 – 12,0
1,61 – 1,91
Table 2. Comparison of mechanical indicators of soils.
Soil type
Relative
collapsibility Ɛsl,
(P = Ϭzg)
The initial
collapsible
pressure.
Psl, kPa
Deformation
modulus
E, MPa
Loam in a natural
occurrence
0,002 – 0,04
22 - 212
9
18
16
Compacted loam
–
–
18 – 41
19 – 31
47 – 87
Drained angle of Total adhesion
internal friction φ,
cw, kPa
degrees
The experiments convincingly indicate that the compacted soil in the pile shaft has
significantly elevated values of physical and mechanical characteristics. The studies on
studying the microstructure of the collapsible and compacted soils have been conducted to
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753
[email protected]
Smolinskiy Nikolay Yakovlevich, Kharchenko Maria Sergeyevna, Kovalenko Tatyana
Anatolyevna, Bormotina Anastasia Mikhailovna, Khalitova Anzira Rustamovna, Mukhin
Andrey Valerievich and Kudinov Artyom Valerievich
solve the problem of the elimination of collapsing characteristics around the pile and to
determine the size of the compacted zone. Microstructural features were evaluated for
samples of the pile shaft, as well as those taken at a distance of 40, 60 and 80 cm from its
outer boundary. The results of the study are presented on electron-scan microscope images
(Pic. 2).
a)
b)
d)
c)
e)
f)
Pic. 2. The microstructure of the collapsible soil under investigation is a) - under
conditions of natural occurrence (before the manufacture of piles); b) - f) - compacted soil
(after making the piles) selected, respectively, from the pile shaft (b) and at distances: 20 cm
from the pile center (c); 40, 60 and 80 cm from the pile shaft (d, e, f).
Studies have shown that the microstructure of rocks turned out to be a sensitive indicator
of the transformations that occurred with collapsible soils during the installation of soil piles,
made with the help of a vibratory pile driver. The transformations that took place led to the
formation of a new, modified microstructure, in many respects different from the original [5,
6]. Studies have revealed a change in the structure of the collapsible soil from the matrix (at
a distance of up to 40 cm) to the skeletal (more than 80 cm) type with a transition zone at a
distance of 40 ÷ 80 cm.
4. CONCLUSIONS
The results of the study leave no doubt that:
1. To eliminate collapsible characteristics of soils and to increase the bearing
capacity of the ground bases during construction on sites of type II conditions on
collapsibility, the method of deep compaction based on the use of an RG
installation can be used;
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Increasing the Base Load-Bearing Capacity Stacked with Soil Type Ii on Collapsibility
2. Soils of the pile shaft and the near the pile shaft massif will have reliable
characteristics of strength and deformation properties, which are several times
higher than these values for soils in natural occurrence.
The results of the study were implemented during the construction of a residential
complex in Chisinau. To eliminate collapsible characteristics of soils and to increase the
bearing capacity of the base, ground piles were made. Pile step was 1.8 m, punching depth
was 10.0 m. It is advisable to continue these studies in order to compile a sample sufficient to
summarize the characteristics of the strength and deformation properties of the compacted
collapsible soils, as well as to develop regional tables. It seems to be necessary to distribute
the offered technical solution for use on sites with a different geological structure.
REFERENCES
[1]
[2]
[3]
[4]
[5]
[6]
[7]
[8]
[9]
[10]
[11]
Bogomolov A.N. Engineering-geological characteristics of loess rocks of the PrutDniester interfluve / A.N. Bogomolov, Yu.I. Olyansky, S.I. Shiyan, T.M. Tikhonova,
O.V. Kiseleva // Bulletin of the Volgograd State University of Architecture and Civil
Engineering. Ser .: Building and architecture. - 2011. - Vol. 24 (43). - with. 33-45.
Olyansky Yu.I. Regularities in the development of the processes of swelling and
subsidence of Neogene-Quaternary clay rocks of the southwest of the Russian platform.
Abstract dis. Dr. geological and mineralogical sciences. - St. Petersburg, 2004. - 47 p.
Manual on the design of the bases of buildings and structures (to Construction Norms &
Regulations 2.02.01-83), Research and Development Establishment in honor of N.M.
Gersevanov. M .: stroiizdat, 1986. - 415 p.
Polkanov V.N. Foundations on subsiding soils. Fundamentals of design and technology of
preparing the grounds: Tutorial / VN Polkanov, A.S. Didenkul, V.I. Toporets. Chisinau:
TUM, 2010. - 94 p.
Karelina I.V., Gumirov M.A., Shvetsov G.I. Computer processing of the electron-scan
microscope images of the microstructure of loess soils // Resource and energy saving as a
motivation for creativity in the architectural and construction process. Proceedings of the
annual meeting of the Russian Academy of Architecture and Construction Sciences 2003.
/ Ed. Col .: V.M. Bondarenko (otv. Ed.), Etc. - Kazan: Ed. KGASA, 2003. - p. 487-489.
Osipov V.I., Sokolov V.N., Rumyantseva N.A. The microstructure of clay rocks / Ed.
EAT.
Sergeyeva. M.: Nedra, 1989. - 211
Slesarev, M.Y. Scientific bases and innovative methods of formation of ecological safety
of construction systems. Abstract of dissertation for the degree of Doctor of Technical
Sciences. Moscow, NRU MGSU – 2007. p. 43.
Telichenko, V.I., Slesarev, M.Y. Ecological Construction Safety Management.
Environmental impact assessment and environmental impact assessment. Tutorial / – M.:
publishinghouse Association building universities. 2005 г. p.441.9
Telichenko V., Slesarev M.U., Kusovkina T.V. The analysis of mythology of the
assessment and ex- pected indicators of ecological air in the Russian Federation for 20102020 years. XXV Polish – Russian – Slovak Seminar “Theoretical Foundation of Civil
Engineering”. Procedia Engineering.153 (2016) s. 736 – 740.
Telichenko V., Slesarev M.U., Kusovkina T.V. The analysis expected indicators of
ecological safety of atmosphere air in the Moscow for 2010-2020 years. XXV Polish –
Russian – Slovak Seminar “The oretical Foundation of Civil Engineering”. Procedia
Engineering.153 (2016) s. 731 – 735.
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Smolinskiy Nikolay Yakovlevich, Kharchenko Maria Sergeyevna, Kovalenko Tatyana
Anatolyevna, Bormotina Anastasia Mikhailovna, Khalitova Anzira Rustamovna, Mukhin
Andrey Valerievich and Kudinov Artyom Valerievich
[12]
[13]
Slesarev M.Y., Kuzovkina T.V., Prospect development methodology of environmental
safety assessment in construction // Social and scientific journal "Ecology of the
urbanized territories», №3. Moscow, 2015. p. 30-36.
Telichenko, V.I., Slesarev, M.Y., Stoikov, V.F. Ecological Construction Safety
Management. Environmental monitoring. Tutorial / – M.: publishing house Association
building universities. 2005 г. p.328.
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