75504
2712-8172
Magazine of Civil Engineering
7
99
2020
1-143
RAR
RUS
9901-9901
Resatalab
Soroush
Department of Civil and Environmental Engineering, Tarbiat Modares University
s.resatalab@modares.ac.ir
Tehran, Iran
Ahmadi
Mohammad Taghi
Department of Civil and Environmental Engineering, Tarbiat Modares University
Mahmadi@modares.ac.ir
Tehran, Iran
Alembagheri
Mohammad
Centre for Infrastructure Engineering, Western Sydney University
Alembagheri@modares.ac.ir
Sydney, Australia
Seismic response sensitivity analysis of intake towers interacting with dam, reservoir and foundation
In this paper, parameter sensitivity analysis of the dynamic response of cylindrical intake towers interacting with the concrete dam, foundation, internal and surrounding water is performed. The tower is modelled and verified using three-dimensional finite elements according to the Eulerian-Lagrangian approach in the time domain. In order to carry out a parametric study, the Taguchi optimization method is employed to distinguish the most influential parameters. Thus, the iteration algorithm and number of numerical tests are designed. The models are tested under longitudinal horizontal excitation of selected reference accelerograms for either hard soil or hard rock. The evaluation of the results indicated that the two parameters, i.e. tower’s slender ratio, and the surrounding water depth are the most effective factors on both intake tower’s top drift and the base shear coefficient under seismic excitations on hard soil. It is observed that the elasticity modulus of the foundation is another influential factor in the seismic response, as the tower’s drift increases with the foundation’s flexibility. Furthermore, the effect of dam interaction on the tower drift reduces as the distance from the dam increases and stays relatively constant for any distance higher than twice the tower’s height. Interesting to note that the intake tower did not show notable sensitivity to the reference hard rock ground motion compared with that of the hard soil ground motion.
10.18720/MCE.99.1
intake tower
interaction intake tower- dam- foundation
seismic response
hydrodynamic pressure
https://engstroy.spbstu.ru/article/2020.99.1/
RAR
RUS
9902-9902
57195495075
0000-0001-6250-1108
Rodriguez Vazquez
Solangel
National Research Moscow State Civil Engineering University
solrusita85@gmail.com
Moscow, Russia
Mokrova
Natalia
National Research Moscow State Civil Engineering University
natali_vm@mail.ru
Moscow, Russia
Spatial analysis methodologies using multicriteria evaluation approaches
Water needs for human and agricultural consumption have increased due to an increase in population and human activities. Identifying potential rainwater harvesting sites (RWHS) is an important step towards maximizing water availability for agriculture and other uses. The selection of suitable sites using computational techniques presents a great challenge, so the present study aimed to examine from a critical approach the different approaches reported, as well as the theoretical references of the topic addressed. Computational spatial analysis methodologies were analyzed using multicriteria evaluation (MCDA) approaches as well as computational technologies such as AHP and WLC supported by GIS). As a result of the study carried out, it was concluded that the identification of areas suitable for certain RWH techniques using improved geomatics techniques remains one of the important purposes of development and research. In addition, the MCDA -GIS combination has the potential to provide a rational, objective and non-biased approach to decision-making in locating potential sites for dam construction.
10.18720/MCE.99.2
rainwater harvesting
AHP-technique
WLC-technique
multi-criteria evaluation
GIS
dams
https://engstroy.spbstu.ru/article/2020.99.2/
RAR
RUS
9903-9903
Lei
Guo
School of Water Conservancy, North China University of Water Resources and Electric Power
glboss@126.com
Zhengzhou, China
Weiping
Shen
School of Water Conservancy, North China University of Water Resources and Electric Power
swpstudy@126.com
Zhengzhou, China
0000-0001-8169-1525
Lixia
Guo
Henan Water Valley Research Institute
guolx@126.com
Zhengzhou, China
Lunyan
Wang
Henan Key Laboratory of Water Environment Simulation and Treatment
982069193@qq.com
Zhengzhou, China
Numerical simulation of concrete dam during heavy rain
In recent years, the frequent extreme weather has led to the rise of reservoir water level, and accordingly changed the reservoir water temperature. As for concrete dams, changes in reservoir water temperature and air temperature may generate temperature stress, and such effect and sudden rise of water level will inevitably change the dam force and endanger the dam safety. By means of numerical simulation and theoretical analysis, this paper analyzed the effect of the extreme rainstorm on the reservoir water level and water temperature, and selected a typical project to simulate the changes of temperature field and stress field of concrete dams in an extreme rainstorm under different working conditions. Results showed that: (1) After the storm flood entered the reservoir, the temperature stress changed little due to the change in the reservoir water temperature; (2) During the rainstorm, the compressive and tensile stresses of concrete dams increased with the time, but did not exceed the allowable values of the concrete used for the dam body; therefore, the dam body was safe; (3) By comparing the effects of the reservoir water level rise caused by heavy rain on the dam stress, the dam temperature stress response varied with the water level rising rate: the greater the reservoir water level rising rate was, the greater the maximum dam response stress was. After being affected by the rainstorm, the dam stresses were the same. Therefore, it was necessary to use a dispatching method to control the rise of the water level. This study can provide theoretical basis and reference for the operation and dispatching of reservoirs during extreme rainstorms.
10.18720/MCE.99.3
dams
finite element method
numerical simulaion
temperature
water level
stress analysis
https://engstroy.spbstu.ru/article/2020.99.3/
RAR
RUS
9904-9904
0000-0001-7416-4428
Ibrahim
Yasser
Prince Sultan University
yibrahim@vt.edu
Riyadh, Saudi Arabia
0000-0003-2823-8275
Abdelsalam
Sayed
Zagazig University
s.salam@link.net
Zagazig, Egypt
0000-0002-6155-3122
Nabil
Marwa
Zagazig University
marwa_nabil_amin@yahoo.com
Zagazig, Egypt
0000-0003-0299-1816
Elsayed
Mahmoud
Zagazig University
eng.me5591@gmail.com
Zagazig, Egypt
Earth pressure reduction on retaining walls using EPS geofoam
Retaining wall structures are widely used in different civil engineering projects including building construction, highways, railways, water conservancy, harbors, and many other projects in order to resist the lateral pressure of soil and water. According to their deformation behavior, retaining walls can be classified as flexible walls and rigid walls. Deformable inclusions such as expanded polystyrene, EPS, geofoam can be used to reduce the lateral earth pressure on retaining wall structures. In this study, the effect of using EPS geofoam inclusion on the reduction of lateral earth pressure and stability behavior of non-yielding and yielding retaining walls with cohesionless backfills is examined through a finite element analysis using ABAQUS software. A parametric analysis was performed to examine the effectiveness of EPS inclusion considering different parameters including the foam thickness, short and long-term characteristics of the foam density, surcharge load on backfill and the backfill properties. According to the results obtained, the earth pressure and subsequently the sliding forces and overturning moments were reduced on non-yielding and yielding retaining walls due to the EPS inclusion. The percentage of reduction was higher in the case of non-yielding walls with zero surcharge pressure. The reduction in sliding forces and overturning moments reached 47 %. Moreover, it was found that the lateral earth pressure, sliding forces and overturning moment on retaining walls were decreased with the increases of the foam thickness. However, the lateral earth pressure was slightly increased with the increase of the foam density. Empirical equations of reduction in lateral forces and overturning moments were developed as a function of foam thickness.
10.18720/MCE.99.4
EPS geofoam
finite element method
non-yielding
yielding walls
lateral earth pressure
ABAQUS
https://engstroy.spbstu.ru/article/2020.99.4/
RAR
RUS
9905-9905
Hajmohammadian Baghban
Mohammad
Department of Manufacturing and Civil Engineering, Norwegian University of Science and Technology (NTNU)
mohammad.baghban@ntnu.no
Gjøvik, Norway
0000-0001-8385-9272
Hashemi
Seyed Amir Hossein
Department of Civil Engineering, Qazvin Branch, Islamic Azad University
hashemi@qiau.ac.ir
Qazvin, Iran
0000-0003-2296-767X
Kalbasi Anaraki
Keyvan
Department of Civil Engineering, Qazvin Branch, Islamic Azad University
kayvan.kalbasi@gmail.com
Qazvin, Iran
0000-0002-7680-5409
Hashemi
Elahesadat
Department of Civil Engineering, Faculty of Engineering, Raja University
Hashemi@raja.ac.ir
Qazvin, Iran
Influence of polypropylene-fiber on the mechanical properties of self-compacting-concrete with recycled aggregates
In this study, the properties of self-compacting concrete (SCC) produced with different percentages of recycled aggregates (RAs) and polypropylene fibers is investigated in comparison with natural aggregates. The effect of using different percentages of 0 %, 25 %, 50 %, 75 % and 100 % RAs instead of natural aggregates (NAs) and polypropylene fibers of 0.1 %, 0.2 % and 0.3 % by volume of concrete in a fresh and hard state, consisting of a total 20 mixture composition, was investigated in SCC. SCC tests in the fresh state, including Slump Flow, J Ring, V Funnel, and L Box and hard concrete tests include compressive, tensile, and flexural and impact tests performed at the age of 28 days. Increasing the use of RAs does not significantly reduce the SCC tests in the fresh state while increasing the fibers causes a significant decrease in tests. In hardened concrete tests, with the increasing use of RAs of concrete, decreasing in compressive strength, tensile strength, flexural strength, and impact resistance were observed. While increasing the percentage of polypropylene fibers in recycled concrete, there was an increase in impact resistance and tensile strength and more energy absorption in the flexural test.
10.18720/MCE.99.5
self-compacting concrete
compressive strength
flexural strength
impact resistance
recycled aggregates
polypropylene fiber
https://engstroy.spbstu.ru/article/2020.99.5/
RAR
RUS
9906-9906
7005670404
Fedosov
Sergey
Ivanovo State Polytechnic University
fedosov-academic53@mail.ru
0000-0001-7405-5651
Loginova
Svetlana
Ivanovo State Polytechnic University
sl79066171227@yandex.ru
Ivanovo, Russia
Mathematical model of concrete biological corrosion
As objects for study samples of cement concrete exposed to biological growth-around have been used. A physical and mathematical model of diffusion processes in system "cement concrete-biofilm-liquid", taking into account the kinetics of the processes of growth, reproduction and death of microorganisms, has been developed. The model of mass transfer in an unlimited two-layer plate in the form of a system of partial differential equations of parabolic type with boundary conditions of the second kind at the boundary of concrete with liquid and the fourth kind at the boundary between concrete and biofilm is considered for the first time. The mathematical model takes into account the kinetics of the change in time of the thickness of the biofilm due to the birth and death of populations of microorganisms. The results of calculations of dimensionless concentrations of “free” calcium hydroxide by the thickness of a concrete structure and biofilm are presented. The results of the numerical experiment showing the influence of mass transfer criteria (Furier, Kirpichov) on the dynamics of corrosive destruction processes have been analyzed. With an increase in the mass transfer criteria of Kirpichov and Furier, large concentration gradients appear. It has been established that carrying out work on cleaning concrete and reinforced concrete underwater structures from biofouling once every 5 years, in conjunction with other scheduled preventive measures, will increase the time between repairs between 1.5 times. Practical recommendations were developed to monitor and increase the corrosion resistance of concrete and reinforced concrete structures in biologically active environments.
10.18720/MCE.99.6
cement
concrete
bio-corrosion
mathematical model
mass transfer
calcium hydroxide
microorganisms
biofilm
https://engstroy.spbstu.ru/article/2020.99.6/
RAR
RUS
9907-9907
0000-0003-4532-719X
Antipov
Vadim
Perm National Research Polytechnic University
seekerva@mail.ru
Perm, Russia
6507708259
0000-0003-0803-2392
Ofrikhter
Vadim
Perm National Research Polytechnic University
ofrikhter@mail.ru
Perm, Russia
Transition factor between elastic and deformation moduli for dispersive soils
The paper is devoted to the perspective trend of researches on estimation of physical and mechanical characteristics of dispersive soils by means of non-destructive methods of in-situ testing by wave analysis. The paper presents the results of comparison of the values of the transition coefficient between the soil dynamic elastic modulus, which can be calculated from the results of in-situ tests by means of non-destructive technique of Multichannel Analysis of Surface Waves, and the soil deformation modulus. Application of such a transition factor makes it possible to estimate the soil deformation modulus according to the soil elastic characteristics determined using modern non-destructive express techniques of wave analysis of the low velocity zone of the upper part of the profile. Due to the application of such express methods, labor and time costs of field investigations are significantly reduced during preliminary geotechnical site assessment. Comparison of different values of the transition factor was made on the basis of the results of laboratory standard triaxial tests and numerical experiments with the values calculated on the basis of dependencies proposed by the results of in-situ tests with Plate Load Tests and Multichannel Analysis of Surface Waves in previous in-situ studies. The results of standard triaxial tests on samples of cohesive and non-cohesive soils confirm the dependence of the transition factor on the soil unit weight, obtained in the previous stage of in-situ researches. The values of the transition factor based on the results of numerical experiments do not exceed the results obtained by field research methods. The results of the research will be useful in estimating the physical and mechanical properties of the soil during preliminary geotechnical calculations of the foundations. All in-situ investigations are carried out using non-destructive technique. No permits or approvals are required to perform the work according to the proposed methodology.
10.18720/MCE.99.7
Multichannel Analysis of Surface Waves
MASW
elastic moduli
deformation modulus
experimental investigations
Plate Load Test
PLT
Triaxial Test
numerical models
https://engstroy.spbstu.ru/article/2020.99.7/
RAR
RUS
9908-9908
0000-0002-7744-6380
Lan
Nguyen Chau
University of Transport and Communications
nguyenchaulan@utc.edu.vn
Vietnam
57205271857
0000-0003-3577-6602
Nguyen
May Huu
University of Transport Technology
maynh@utt.edu.vn
Vietnam
0000-0002-4001-9246
Bui
Tien Thanh
University of Transport and Communications
btthanh@utc.edu.vn
Vietnam
Long
Nguyen Ngoc
University of Transport and Communications
nguyenngoclong@utc.edu.vn
Vietnam
Tien
Le Duc
University of Transport and Communications
ductiensogtvtqt@gmail.com
Vietnam
57191583880
0000-0002-6012-6460
Ho
Lanh Si
Civil and Environmental Engineering Program, Graduate School of Advanced Science and Engineering, Hiroshima University
lanhhs@utt.edu.vn
Higashi-Hiroshima, Hiroshima, Japan
Bearing capacity of drilled shaft in intermediate geomaterials
Weathered rock or IGMs (Intermediate Geomaterials) is still a controversy in designing the bearing capacity of the drilled shaft. At present, Vietnamese standards separately defined the load capacity of the pile in soils and rocks. That leads to both underestimation and overestimation in case IGMs assumed to be soil and rock, respectively. In this paper, a case study of a project in central Vietnam basing on experienced equations, finite element method (FEM), and field measurement was conducted. The static loading and pull-out tests were conducted for drilled shaft with 0.8 m in diameter installing in the weathered rock. In these tests, instruments were installed including the displacement device, strain gage, and extensometers, which were distributed along the drilled shaft to measure the side and tip bearing capacity of the piles. In addition, FEM was employed to simulate the static loading and pull-out tests of the piles. The obtained results indicated that FEM had a similar behavior at the medium loading stage compared to the field tests (static loading and pull-out tests). Thus, FEM could be a potential method that can be used for calculating and estimating the bearing capacity of the drilled shaft in the IGMs layer. An empirical equation was proposed for computing the side resistance of the pile in the IGMs layer. Finally, this study could help to choose properly the pile length in the design of the pile placed on IGMs layer so that the safety and cost-effective problems can be optimized.
10.18720/MCE.99.8
drilled shaft
weathered rock
intermediate geomaterials
bearing capacity
static loading test
FEM
FB-MultiPier
https://engstroy.spbstu.ru/article/2020.99.8/
RAR
RUS
9909-9909
56296687300
0000-0002-2299-3096
Rybakov
Vladimir
Peter the Great Saint Petersburg Polytechnic University
fishermanoff@mail.ru
Polytechnicheskay, 29
Sovetnikov
Daniil
Bryden Wood Technology Ltd
sovetnikov.daniil@gmail.com
London, UK
0000-0003-2067-5585
Jos
Vladislav
Peter the Great St. Petersburg Polytechnic University
jos_vlad@mail.ru
St. Petersburg, Russia
Bending torsion in Γ-shaped rigid and warping hinge joints
This paper investigates the effect of bending torsion which is the cross-sectional warping of thin-walled rods at plane frame joints in the framework of the “semi-shear” theory of V.I. Slivker. Studied are the shell finite element models of rigid and “warping hinge” joints in thin-walled bar structures, designed and calculated in the software package Ansys Workbench. The correlation of the geometric characteristics of thin-walled profiles and the connecting plate is considered towards the change in the value of normal stresses and bimoments when the cross-sectional axis is rotated. The obtained ratios of the bimoment stresses before and after the rotation of the cross-sectional axis of the joints are presented. The study concentrates the distribution of the bimoments and warpings in the plane frame with rigid joints with and without the consideration of the coefficient of the cross-sectional axis rotation. The comparison of the obtained results for both cases is shown.
10.18720/MCE.99.9
lightweight gauge steel structures
warping hinge
plane frame
thin-wall rods
Slivker’s semi-shear theory
rigid joint
bimoment
warping
https://engstroy.spbstu.ru/article/2020.99.9/
RAR
RUS
9910-9910
6504446571
0000-0001-6981-7420
Al-Rousan
Rajai
Jordan University of Science and Technology
rzalrousan@just.edu.jo
Irbid, Jordan
Behavior of B-C connections damaged by thermal shock
The behavior of beam-column (B-C) connections received thorough investigation during the past decades focusing on critically-detailed connections before and after strengthening. Exposure of such B-C connections to thermal shock due to subjected to cycles of heating–cooling such as in chimneys, concrete foundations for launching rockets carrying spaceships, concrete near to furnace, clinker silos and nuclear power plants, or those subjected to fire then extinguished using water would aggravate the weakness of the high joint zone. In this study, systematic nonlinear finite element analyses (NLFEA) were conducted using ANSYS to evaluate the effects of the level of the column axial load and thermal shock impact which is a parameter difficult to evaluate experimentally due to limitations in loading machines and requirement for complicated testing setups. A total of eight NLFEA models were created, calibrated and properly verified with reputable experimental literature results. The NLFEA results showed that both level of the column axial load and thermal shock impact significantly affect the cracks distribution, failure mode, ultimate load capacity, and ductility of the B-C connection. Column axial load levels up to 75 % were advantageous to the behavior of virgin B-C connections. The lateral load capacities, net drifts, hysteresis loops, cracks distribution, energy dissipation, and failure modes were presented.
10.18720/MCE.99.10
reinforced concrete
thermal shock
structural strength
horizontal load
fiber reinforced polymer
nonlinear
finite element analysis
https://engstroy.spbstu.ru/article/2020.99.10/
RAR
RUS
9911-9911
Aniskin
Nikolay
National Research Moscow State Civil Engineering University.
nikolai_aniskin@mail.ru
26 Yaroslavskoye av., Moscow, 129337 Russia
57203962119
0000-0001-9723-5161
Nguyen
Trong-Chuc
National Research Moscow State Civil Engineering University
ntchuc.mta198@gmail.com
The effect of formworks on the temperature regime in the mass concrete
This paper presents the results of numerical studies about the temperature regime and thermal stress state of an erected concrete block with various design forms of formwork. The influence of formwork on the formation of the temperature regime is considered taking into account the influence of the main factors: the air temperature, the cement consumption per cubic meter of concrete and its maximum heat dissipation. An assessment of the risk of temperature cracks is given for three formwork cases: metal (steel) and wooden without thermal insulation and with insulation. Based on the results obtained, nomograms are constructed in order to estimate the temperature difference between the center of the concrete mass and its surface, depending on the values of the factors. It is shown that under the considered conditions during construction from the point of view of temperature crack formation, wooden formwork is more preferable than metal (steel). Thus, when concreting in the cold season and using a large amount of cement or large-heat cement then formwork insulation is necessary. In this work, results from the nomograms are obtained may be used as reference material in the design and construction of mass concrete structures such as dams, foundations, bridge supports, etc.
10.18720/MCE.99.11
temperature regime
thermally stressed state
concrete mass
temperature crack formation
formwork
https://engstroy.spbstu.ru/article/2020.99.11/
RAR
RUS
9912-9912
M-6585-2013
6508103761
0000-0002-1196-8004
Vatin
Nikolai
Peter the Great Saint Petersburg Polytechnic University
vatin@mail.ru
Polytechnicheskay, 29
57190967764
Gubaydulin
Rafkat
South Ural State University
gubaidulinrg@susu.ru
Chelyabinsk, Russia
Tingaev
Aleksandr
South Ural State University
tingaevak@susu.ru
Chelyabinsk, Russia
Flange connections with high-strength bolts with technological heredity of bolts
Tubular truss and column members with bolted connections widely used in construction. The object of this research was the flange joint of a truss bottom chord. The flange joint coaxially connects two cold-formed closed welded rectangular hollow section profiles. The flange connects with high-strength bolts of strength class 10.9. The stress-strain state of the joint was numerically and experimentally investigated. Experimental studies were performed on a full-size sample of a flange joint using strain gauges. Numerical calculations were performed at ANSYS. The bilinear isotropic hardening model simulated the metal elements performance of the joint. The “Frictional” model was chosen for the friction forces between the flanges. The microstructure of the bolt material was studied using an optical microscope. The study results showed that the model solution for a flanged provides a uniform distribution of stresses at the junction due to its spatial rigidity. The presence of stiffener ribs provides the absence of the clearance between the flanges and promotes the joint performance of welded units and high-strength bolts. The design of the flange joint using the developed finite element model indicates that the results of numerical and experimental studies are sufficient for practical application. The difference between finite element model calculations and experimental data in the most loaded elements of flange joints does not exceed 10 %. It is proposed for high-strength bolts of strength class 10.9 and higher to introduce regulatory restrictions on the number and size of non-metallic inclusions that affect the delayed brittle fracture of bolts. To improve the performance that bolts, it is proposed to use steel grades with a bainitic or bainitic-martensitic structure, which are formed by microalloying them with molybdenum, vanadium, niobium, titanium, boron and heat treatment.
10.18720/MCE.99.12
delayed brittle fracture
finite element method
flanges
high-strength bolts
joints
non-metallic inclusions
steel structures
stiffness
stress-strain state
struct
https://engstroy.spbstu.ru/article/2020.99.12/
RAR
RUS
9913-9913
Toropov
Aleksandr
Saint Petersburg State Forest Technical University under name of S.M. Kirov
Toropov_A_S@mail.ru
St. Petersburg, Russia
Byzov
Viktor
St. Petersburg State University of Architecture and Civil Engineering
mapana@inbox.ru
St. Petersburg, Russia
36884074300
0000-0002-2583-3012
Melekhov
Vladimir
Northern (Arctic) Federal University named after M.V. Lomonosov
v.melekhov@narfu.ru
Arkhangelsk, Russia
Deformations during drying of wooden corner elements of I-beams
At present, environmental degradation is occurring, which affects forests. Increasingly, in the trunks of conifers there is core (sound) rot. Round timber with sound rot is left in the forest, which does not contribute to improving the environmental situation. A new technological process is proposed for producing lumber from round timber with sound rot for the manufacture of structural elements for construction. In the process of cutting, the rot is removed, and the elements of the angular cross section are obtained. In the future, they are used for the manufacture of I-beams. A method of drying elements of an angular cross section in convection chambers of periodic action is considered. Samples were made in which the change in the angles of the inner quarter was measured. Samples were dried to a moisture content of 6 ± 2%. During drying, the samples were fixed in pairs using clamps (clamps). It is established that the deviation of the angles of the side of the quarter of the bar of the angular cross section increases with increasing size of the quarter. The transverse warping of the pressed samples is much less than that of the samples without pressure. The optimal size of the core (core) rot should be 30-35% of the diameter of the round assortment at the top. Such rot sizes at the corresponding quarter sizes do not lead to significant allowances for machining and loss of volumes of high-quality structural wood.
10.18720/MCE.99.13
core rot
the round assortments
drying of lumber
angular cross-sectional elements
supporting building structures
lateral warping of lumber
https://engstroy.spbstu.ru/article/2020.99.13/