75504
2712-8172
Magazine of Civil Engineering
2
86
2019
1-118
RAR
RUS
3-10
57193760645
0000-0002-4701-3840
Karaganda State Technical University
Baydjanov
Djumageldy
BDO3@yandex.ru
Karaganda State Technical University
Abdrakhmanova
Kalamkas
kagaip@mail.ru
56, Mira blvd, Karaganda, Republic of Kazakhstan, 100027
Karaganda State Technical University
Kropachev
Pyotr
kropachev-54@mail.ru
56, Mira blvd, Karaganda, Republic of Kazakhstan, 100027
Karaganda State Technical University
Rakhimova
Galiya
galinrah@mail.ru
56, Mira blvd, Karaganda, Republic of Kazakhstan, 100027
Modified concrete for producing pile foundations
There are considered the issues of structural modification of heavy concrete with oligomer-polymer additives. It has been established that crystallization of the cement stone proceeds at macro- and micro-levels. Macro-pores are filled with products of crystallization of cement particles grafted on the surface of polyvinyl chloride (PVC) macromolecules. The migration of PVC macromolecules and oligomers of the waste of coke-chemical production (WCP) into defective zones is due to the occurrence of internal stresses during hardening and volumetric compression which causes the closure of macro- and micro-pores, as well as cracks and capillaries. Thus, for the complex of physical and mechanical properties, resistance to sulfate corrosion and frost resistance the studied concrete based on structurally modified concrete can be used for producing pile foundations arranged in conditions of highly saline soils. The presented results of experimental studies indicate sufficient corrosion resistance of the concrete under study
10.18720/MCE.86.1
modified concrete
additives
reinforced concrete pile foundations
resistance to corrosive environments
sulfate corrosion
water-tightness
concrete durability
ground water
https://engstroy.spbstu.ru/article/2019.86.1/
01.pdf
RAR
RUS
11-19
Saint Petersburg State Forest Technical University under name of S.M. Kirov
Toropov
Aleksandr
Toropov_A_S@mail.ru
St. Petersburg, Russia
St. Petersburg State University of Architecture and Civil Engineering
Byzov
Viktor
mapana@inbox.ru
St. Petersburg, Russia
36884074300
0000-0002-2583-3012
Northern (Arctic) Federal University named after M.V. Lomonosov
Melekhov
Vladimir
v.melekhov@narfu.ru
Arkhangelsk, Russia
Manufacturing structural building components from round timber with heartwood rot
Coniferous sawn goods are widely used in construction industry. The quality of round timber deteriorates due to the presence of heartwood rot, which has to be removed in the manufacture of load-bearing structural units. As a rule, rot is removed during the round timber logging. At the same time, healthy sapwood is removed along with that impacted by rot. Therefore, large amounts of quality wood remain in forests. For qualitative ripping of round timber affected by heartwood rot, it is necessary to know the rot shape and size in trunks. The relationship between the round timber cross-sectional dimensions and heartwood rot size along the trunk length is quite accurately described by correlative (allometric) growth equations. As a result of the research, such interrelations were established. Based on the equations obtained, conditional ripping of round log was carried out. As a result, bars for manufacturing I-beams were obtained. They are widely used in lowrise wooden house construction. It was established that the recovery factor was high enough for structural units made of round timber affected by heartwood rot that makes it possible to propose this cutting method for industrial application.
10.18720/MCE.86.2
round timber
heartwood rot
allometric growth equations
structural building components
the yield of T-section units
https://engstroy.spbstu.ru/article/2019.86.2/
02.pdf
RAR
RUS
20-29
Tampere University of Technology
Pajunen
Sami
sami.pajunen@tut.fi
Tampere University
Hautala
Janne
janne.hautala@tuni.fi
Tampere, Finland
Tampere University of Technology
Heinisuo
Markku
markku.heinisuo@tut.fi
Tampere, Finland
Modelling the stressed skin effect by using shell elements with meta-material model
It is a well-known fact that the so-called stressed skin design results in ca. 10–20 % mass and cost savings in a typical steel hall structures. The potential of this design method is however, too often disregarded due to e.g. rather complex and limited existing design rules and instructions. In this paper, a method for determination of generalized elastic parameters is proposed, so that the stressed skin can be modelled in the general finite element software using existing elements and material parameters. With the proposed method, structural designer can take advantage of the stressed skin design in the context of basic design tools as Autodesk Robot or RFEM.
10.18720/MCE.86.3
stressed skin
diaphragm
corrugated sheet
https://engstroy.spbstu.ru/article/2019.86.3/
03.pdf
RAR
RUS
30-45
9244185400
Tashkent institute of irrigation and agricultural mechanization engineers
Khudayarov
Bakhtiyar
bakht-flpo@yandex.ru
39, Kari-Niyazova, Tashkent, 100000, Uzbekistan
Tashkent institute of irrigation and agricultural mechanization engineers
Turaev
Fozil
t.fozil86@mail.ru
39, Kari-Niyazova, Tashkent, 100000, Uzbekistan
Nonlinear vibrations of fluid transporting pipelines on a viscoelastic foundation
The article presents the results of a study of vibration process in pipelines conveying fluid or gas. A mathematical model pipeline was used in the form of cylindrical shell and a viscoelastic foundation in the form of two-parameter model of the Pasternak. The hereditary Boltzmann-Volterra theory of viscoelasticity is used to describe viscoelastic properties. The effects of the parameters of the Pasternak foundations, the singularity in the heredity kernels and geometric parameters of the pipeline on vibrations of structures with viscoelastic properties are numerically investigated. It is found that an account of viscoelastic properties of the pipeline material leads to a decrease in the amplitude and frequency of vibrations by 20–40 %. It is shown that an account of viscoelastic properties of soil foundations leads to a damping of vibration process in pipeline.
10.18720/MCE.86.4
vibration process
foundation
pipeline
mathematical model
numerical algorithm
cylindrical shell
https://engstroy.spbstu.ru/article/2019.86.4/
04.pdf
RAR
RUS
46-60
Czech Technical University
Hrbek
Vladimir
hrbek@fsv.cvut.cz
Thakurova 7, 166 29 Prague, Czech Republic
0000-0003-3750-5005
Czech Technical University
Bily
Petr
petr.bily@fsv.cvut.cz
Thakurova 7, 166 29 Prague, Czech Republic
0000-0001-8281-3053
Czech Technical University
Fladr
Josef
fladr@fsv.cvut.cz
Thakurova 7, 166 29 Prague, Czech Republic
0000-0001-5497-0705
Czech Technical University
Chylik
Roman
chylik@fsv.cvut.cz
Prague, Czech Republic
Czech Technical University
Vrablik
Lukas
vrablik@fsv.cvut.cz
Thakurova 7, 166 29 Prague, Czech Republic
The effect of cement replacement and homogenization procedure on concrete mechanical properties
Supplementary cementitious materials (SCM) are used in concrete for two main reasons – to reduce the amount of cement used and to improve material properties. A material that is more sustainable, durable, environmental friendly and economical compared to the traditional Portland cement concrete can be obtained. This paper investigates the effect of two important factors on mechanical properties of highperformance concrete (HPC) containing SCM. The first factor is the content of selected SCM, the second one is the homogenization procedure used for preparation of concrete. In the first part of the research program, 10 different mixtures were compared: reference mixture with no SCM and mixtures where 10 %, 20 % or 30 % of cement weight were replaced by microsilica, fly ash or metakaolin. In the second part, three mixtures with selected replacement levels were prepared by four different homogenization procedures and studied. Tests of bulk density, compressive strength, splitting tensile strength, flexural tensile strength, dynamic and static elastic modulus and depth of penetration of water under pressure were carried out for the tested mixtures. The best results were reached when cement was partially replaced by fly ash. Resistance of concrete to penetration of water under pressure was significantly improved by all SCM. The homogenization procedure in which the SCM was added to the mixture after water led to slightly better properties than the standard mixing technique in case of mixtures containing microsilica and metakaolin. The paper provides an extensive database that can serve as a benchmark for the design of HPC containing SCM.
10.18720/MCE.86.5
high-performance concrete
supplementary cementitious materials
fly ash
microsilica
metakaolin
https://engstroy.spbstu.ru/article/2019.86.5/
05.pdf
RAR
RUS
61-71
57209739736
Shenyang Jianzhu University
Chao
Guo
guochaoglovel@126.com
55490061300
Shenyang Jianzhu University
Lu
Zhengran
luzhengranglovel@126.com
Frost heaving of foundation pit for seasonal permafrost areas
Frost heaving can cause support structures to crack and even instability of the foundation pit. This paper describes the frost heaving features of the steel pile pre-stressed tendon composite foundation pit support system (SPPTCFPSS). As a combined rigid–flexible support system during the overwintering stage in Northeast China, these systems were used to investigate the transient heat conduction and fixed boundary one-dimensional frost heaving stress equations. The axial force sensors of the tendons used for the in-situ test accurately recorded the changing values of the axial forces of the pre-stressed tendons during the integrated working period for the foundation pit frost-heaving effect. Practical support data for the frost heaving stress analysis of the system were thus provided. The thermo-physical properties were obtained from the soil experiments, including the coefficient of thermal conductivity, specific heat of the foundation soil, and thermal expansion factor, among others. Base on this, the fluid effective velocity, saturation, and temperature fields were received from the heat flow coupling analysis of finite element methods (FEM).The results show that the actual axial force applied to the SPPTCFPSS is approximately equal to the theoretical value of the pit frost-heaving force calculated for the one-dimensional fixed boundary conditions corrected by saturation index from FEM. The SPPTCFPSS can adapt to a large-scale frost-heaving deformation to enable a reasonable increase in adaptive capacity in a region that has seasonal periods of frozen soil.
10.18720/MCE.86.6
frost heaving
foundation pit
temperature field
temperature stress
https://engstroy.spbstu.ru/article/2019.86.6/
06.pdf
RAR
RUS
72-82
Siberian State Automobile and Highway University
Lunev
Aleksandr
lunev.al.al@gmail.com
Siberian State Automobile and Highway University
Sirotyuk
Victor
sirvv@yandex.ru
Stress distribution in ash and slag mixtures
In the design of roads, a number of engineering tasks that requires determining the stress state of the road structure are solved: estimating the stability of the embankment, calculating the load resistance, predicting deformations, determining the loads affecting on the culverts and communication lines in the body of the roadbed, etc. The solution of these tasks in the design of ash and slag mixture embankments cannot be performed due to the insufficient knowledge of the stress state formation mechanisms in similar solids. The article reviews and compares theoretical solutions for predicting stresses in a continuous and granular environment arising in the body under the flat plate effect on its surface. The tests were carried out on a solid with a compaction coefficient (0.95), with five values of humidity (from 22 to 38 % by weight). The results of experimental studies on the change in pressure arising in the ASM at different depths, when exposed to the vertical load from the stamp, are presented. The value of the shear resistance to increase by 21 % with an increase in moisture content from 22 % to 28 %, and with further growth returned to almost the original values without any visible effect on the stress distribution. Conclusions about the insignificant effect of humidity on the stress distribution in the ASM were drawn (at least under the chosen experimental conditions). Estimates of mathematical models for stress prediction in relation to the bulk body from the ash and slag mixture are given. To determine the distribution environment coefficient in the Fröhlich model, a correlation dependence between the CBR and the modulus of elasticity was derived. This correlation allowed us to link the theoretical solutions of Gonzalez and earlier experiments on the evaluation of the modulus of elasticity of embankments from ASM at different humidity with the stresses distribution.
10.18720/MCE.86.7
construction
coal ash
ash and slag mixture (ASM)
mathematical modeling
https://engstroy.spbstu.ru/article/2019.86.7/
07.pdf
RAR
RUS
83-91
0000-0002-2440-9754
Central South University
Zhao
Yiding
zhaoyiding89@126.com
Changsha City, Hunan Province, China
0000-0002-5905-5175
Cccc Second Harbour Eingineering Company Design & Research Institute Co.
Shi
Yao
734169065@qq.com
Wuhan, China
Central South University
Yang
Junsheng
1797935162@qq.com
Cracking of tunnel bottom structure influenced by carbonaceous slate stratum
Constructing tunnel is a difficult and expensive process which deserves special attention. In this article, cracking behavior in a highway tunnel structure during construction period is researched, including figuring out the causes and evolution of crack. Large deformation of rock mass is the major inducement of the damaging behavior, which is obtained from the field investigation. The layers of the ground were monitored with the displacement of tunnel while the numerical analysis was realized with extended finite element method. The results highlight the regions of cracking on tunnel bottom structure, which emphasizes the accuracy of model and the influence of poor geological condition. This work demonstrates that the carbonaceous slate stratum plays an important role in the stability of tunnel structure, which leads to the phenomenon of stress concentration in tunnel bottom region. Moreover, the implemented numerical model also simulates the process of the damaging behaviors of tunnel structure induced by the poor geological condition, which is similar to the results from field investigation and provides the design basis for maintenance work.
10.18720/MCE.86.8
carbonaceous slate
cracking
tunnel bottom structure
numerical analysis
https://engstroy.spbstu.ru/article/2019.86.8/
08.pdf
RAR
RUS
92-104
St. Petersburg State University of Architecture and Civil Engineering
Morozov
Valery
morozov@spbgasu.ru
2-nd Krasnoarmeiskaya St. 4, 190005 St. Petersburg, Russia
57191250155
0000-0002-7796-2350
St. Petersburg State University of Architecture and Civil Engineering
Opbul
Eres
fduecnufce@mail.ru
St. Petersburg, Russia
St. Petersburg State University of Architecture and Civil Engineering
Van Phuc
Phan
phucprodhv@gmail.com
2-nd Krasnoarmeiskaya St. 4, 190005 St. Petersburg, Russia
Behaviour of axisymmetric thick plates resting against conical surface
The present article is dedicated to analytical and numerical investigation of behavior of end elements of high-pressure casings for nuclear reactors. Nuclear energy generated inside the high-pressure casings will become an actual power-related choice of the human kind in the very near future. In this respect, development of methodology for proper calculation of axisymmetric plates resting against conical surface and bearing the evenly distributed load is becoming state of the art issue. In order to perform analytical calculation the authors used established concrete strength criteria and prerequisites assumed, while ANSYS WORKBENCH software package was applied to calculate the ultimate load value and stress state. Calculations were made considering a keyed connection between thick plate and load-bearing wall of the high-pressure casing and referring to considerably high, in one case, and low (variable), in the other case, plate stiffness. The article presents comparative analysis of calculation results that demonstrates calculation methods adequacy. The authors developed original methods of analytical and numerical calculations allowing to investigate stress state of end elements designed in the form of axisymmetric plates resting against conical surfaces. End elements behavior in load condition is characterized by formation of spheric vault where stress condition typical for concrete three-dimensional compression state occurs. Investigations presented show that sudden disintegration does not occur when concrete end elements are affected by cracks in the stretched area; instead, the spheric vault is formed. Strength of such spheric vault occurring in the element is rather depending upon load bearing wall stiffness, i.e. the lower the stiffness the smaller the strength and vice versa. The following scientific results have been obtained: – end elements shaped as thick axisymmetric plates in condition of ultimate load are characterized by spheric vault formation; -authors, based on assumptions and guided by approximate procedure have obtained the formula for spheric vault thickness calculation; – authors obtained original methods of analytical and numerical calculation to evaluate stress condition of high-pressure casings’ end elements shaped as thick axisymmetric plates resting against conical surface; – comparison of calculation results displays minor discepancies between analytical and numerical calculation models.
10.18720/MCE.86.9
high-pressure casing
end element
axisymmetric plate
bearings
walls (structural partitions)
internal pressure
loads (forces)
key
conical surface
https://engstroy.spbstu.ru/article/2019.86.9/
09.pdf
RAR
RUS
105-118
Semnan University
Arshadi
Hamed
hamed.arshadi@semnan.ac.ir
Semnan, Iran
0000-0001-7802-2013
Semnan University
Kheyroddin
Ali
kheyroddin@semnan.ac.ir
Semnan, Iran
Shear lag phenomenon in the tubular systems with outriggers and belt trusses
Development of technology facilitates construction of tall buildings. One of the common kinds of them is Tubular systems, divided into different types: framed tube, tube-in-tube, trussed tube and bundled tube systems. The main problem of tubular systems is the shear lag phenomenon that decreases the bending rigidity and moment resistance of the structures. In this paper, the phenomenon of shear lag in all kinds of steel tube systems is investigated analytically. In order to reach this objective, sixteen steel multi-storey tubular structures with the same plan, but a with a different number of stories and different tubular systems were designed by ETABS software based on AISC. Then the shear lags of each structure in different elevations are calculated by using the linear response spectrum analysis. The results show that nearly in the upper half of the structures the negative shear lag happens. Besides all, the formula was derived for each system with regard to the analyses data with linear regression examine by SPSS software, which showed that there is a significant relation between shear lag and three independent variables: story number, height ratio and distance from the web of the structures.
10.18720/MCE.86.10
framed tube system
tube-in-tube system
trussed tube system
bundled tube system
shear lag
https://engstroy.spbstu.ru/article/2019.86.10/
10.pdf